Find, fix and prevent vulnerabilities in your code.

Overview

com.fasterxml.jackson.core:jackson-databind is a library which contains the general-purpose data-binding functionality and tree-model for Jackson Data Processor.

Affected versions of this package are vulnerable to XML External Entity (XXE) Injection. A flaw was found in FasterXML Jackson Databind, where it does not have entity expansion secured properly in the DOMDeserializer class. The highest threat from this vulnerability is data integrity.

Details

XXE Injection is a type of attack against an application that parses XML input. XML is a markup language that defines a set of rules for encoding documents in a format that is both human-readable and machine-readable. By default, many XML processors allow specification of an external entity, a URI that is dereferenced and evaluated during XML processing. When an XML document is being parsed, the parser can make a request and include the content at the specified URI inside of the XML document.

Attacks can include disclosing local files, which may contain sensitive data such as passwords or private user data, using file: schemes or relative paths in the system identifier.

For example, below is a sample XML document, containing an XML element- username.

<xml>
<?xml version="1.0" encoding="ISO-8859-1"?>
   <username>John</username>
</xml>

An external XML entity - xxe, is defined using a system identifier and present within a DOCTYPE header. These entities can access local or remote content. For example the below code contains an external XML entity that would fetch the content of /etc/passwd and display it to the user rendered by username.

<xml>
<?xml version="1.0" encoding="ISO-8859-1"?>
<!DOCTYPE foo [
   <!ENTITY xxe SYSTEM "file:///etc/passwd" >]>
   <username>&xxe;</username>
</xml>

Other XXE Injection attacks can access local resources that may not stop returning data, possibly impacting application availability and leading to Denial of Service.

Remediation

Upgrade com.fasterxml.jackson.core:jackson-databind to version 2.6.7.4, 2.9.10.7, 2.10.5.1 or higher.

References

• GitHub Commit
• GitHub Issue
• RedHat Bugzilla Bug

Overview

com.fasterxml.jackson.core:jackson-databind is a library which contains the general-purpose data-binding functionality and tree-model for Jackson Data Processor.

Affected versions of this package are vulnerable to Deserialization of Untrusted Data. It mishandles the interaction between serialization gadgets and typing, related to org.apache.commons.dbcp2.datasources.PerUserPoolDataSource.

Details

Serialization is a process of converting an object into a sequence of bytes which can be persisted to a disk or database or can be sent through streams. The reverse process of creating object from sequence of bytes is called deserialization. Serialization is commonly used for communication (sharing objects between multiple hosts) and persistence (store the object state in a file or a database). It is an integral part of popular protocols like Remote Method Invocation (RMI), Java Management Extension (JMX), Java Messaging System (JMS), Action Message Format (AMF), Java Server Faces (JSF) ViewState, etc.

Deserialization of untrusted data (CWE-502), is when the application deserializes untrusted data without sufficiently verifying that the resulting data will be valid, letting the attacker to control the state or the flow of the execution.

Java deserialization issues have been known for years. However, interest in the issue intensified greatly in 2015, when classes that could be abused to achieve remote code execution were found in a popular library (Apache Commons Collection). These classes were used in zero-days affecting IBM WebSphere, Oracle WebLogic and many other products.

An attacker just needs to identify a piece of software that has both a vulnerable class on its path, and performs deserialization on untrusted data. Then all they need to do is send the payload into the deserializer, getting the command executed.

Developers put too much trust in Java Object Serialization. Some even de-serialize objects pre-authentication. When deserializing an Object in Java you typically cast it to an expected type, and therefore Java's strict type system will ensure you only get valid object trees. Unfortunately, by the time the type checking happens, platform code has already created and executed significant logic. So, before the final type is checked a lot of code is executed from the readObject() methods of various objects, all of which is out of the developer's control. By combining the readObject() methods of various classes which are available on the classpath of the vulnerable application, an attacker can execute functions (including calling Runtime.exec() to execute local OS commands).

Remediation

Upgrade com.fasterxml.jackson.core:jackson-databind to version 2.9.10.8 or higher.

References

• GitHub Issue

Overview

com.fasterxml.jackson.core:jackson-databind is a library which contains the general-purpose data-binding functionality and tree-model for Jackson Data Processor.

Affected versions of this package are vulnerable to Deserialization of Untrusted Data. It mishandles the interaction between serialization gadgets and typing, related to org.apache.commons.dbcp2.datasources.SharedPoolDataSource.

Details

Serialization is a process of converting an object into a sequence of bytes which can be persisted to a disk or database or can be sent through streams. The reverse process of creating object from sequence of bytes is called deserialization. Serialization is commonly used for communication (sharing objects between multiple hosts) and persistence (store the object state in a file or a database). It is an integral part of popular protocols like Remote Method Invocation (RMI), Java Management Extension (JMX), Java Messaging System (JMS), Action Message Format (AMF), Java Server Faces (JSF) ViewState, etc.

Deserialization of untrusted data (CWE-502), is when the application deserializes untrusted data without sufficiently verifying that the resulting data will be valid, letting the attacker to control the state or the flow of the execution.

Java deserialization issues have been known for years. However, interest in the issue intensified greatly in 2015, when classes that could be abused to achieve remote code execution were found in a popular library (Apache Commons Collection). These classes were used in zero-days affecting IBM WebSphere, Oracle WebLogic and many other products.

An attacker just needs to identify a piece of software that has both a vulnerable class on its path, and performs deserialization on untrusted data. Then all they need to do is send the payload into the deserializer, getting the command executed.

Developers put too much trust in Java Object Serialization. Some even de-serialize objects pre-authentication. When deserializing an Object in Java you typically cast it to an expected type, and therefore Java's strict type system will ensure you only get valid object trees. Unfortunately, by the time the type checking happens, platform code has already created and executed significant logic. So, before the final type is checked a lot of code is executed from the readObject() methods of various objects, all of which is out of the developer's control. By combining the readObject() methods of various classes which are available on the classpath of the vulnerable application, an attacker can execute functions (including calling Runtime.exec() to execute local OS commands).

Remediation

Upgrade com.fasterxml.jackson.core:jackson-databind to version 2.9.10.8 or higher.

References

• GitHub Issue

Overview

com.fasterxml.jackson.core:jackson-databind is a library which contains the general-purpose data-binding functionality and tree-model for Jackson Data Processor.

Affected versions of this package are vulnerable to Deserialization of Untrusted Data. It mishandles the interaction between serialization gadgets and typing, related to com.oracle.wls.shaded.org.apache.xalan.lib.sql.JNDIConnectionPool (aka embedded Xalan in org.glassfish.web/javax.servlet.jsp.jstl).

Details

Serialization is a process of converting an object into a sequence of bytes which can be persisted to a disk or database or can be sent through streams. The reverse process of creating objects from a sequence of bytes is called deserialization. Deserialization of untrusted data (CWE-502) occurs when an application deserializes untrusted data without sufficiently verifying that the resulting data will be valid, allowing the attacker to control the state or the flow of the execution.

com.fasterxml.jackson.core:jackson-databind allows deserialization of JSON input to Java objects. If an application using this dependency has the ability to deserialize a JSON string from an untrusted source, an attacker could leverage this vulnerability to conduct deserialization attacks.

Exploitation of unsafe deserialization attacks through jackson-databind requires the following prerequisites:

1. The target application allowing JSON user input which is processed by jackson-databind

An application using jackson-databind is only vulnerable if a user-provided JSON data is deserialized.

2. Polymorphic type handling for properties with nominal type are enabled

Polymorphic type handling refers to the addition of enough type information so that the deserializer can instantiate the appropriate subtype of a value. Use of "default typing" is considered dangerous due to the possibility of an untrusted method (gadget) managing to specify a class that is accessible through the class-loader and therefore, exposing a set of methods and/or fields.

3. An exploitable gadget class is available for the attacker to leverage

Gadget chains are specially crafted method sequences that can be created by an attacker in order to change the flow of code execution. These gadgets are often methods introduced by third-party components which an attacker could utilise in order to attack the target application. Not every gadget out there is supported by jackson-databind. The maintainers of jackson-databind proactively blacklists possible serialization gadgets in an attempt to ensure that it is not possible for an attacker to chain gadgets during serialization.

Further reading:

• On Jackson CVEs: Don’t Panic on Medium
• NCC Group Jackson Deserialization WhitePaper
• Java Security Best Practices

Remediation

Upgrade com.fasterxml.jackson.core:jackson-databind to version 2.9.10.8 or higher.

References

• GitHub Issue
• Medium Post
• PoC

Overview

com.fasterxml.jackson.core:jackson-databind is a library which contains the general-purpose data-binding functionality and tree-model for Jackson Data Processor.

Affected versions of this package are vulnerable to Deserialization of Untrusted Data. The package mishandles the interaction between serialization gadgets and typing, related to org.apache.tomcat.dbcp.dbcp.datasources.SharedPoolDataSource.

Details

Serialization is a process of converting an object into a sequence of bytes which can be persisted to a disk or database or can be sent through streams. The reverse process of creating objects from a sequence of bytes is called deserialization. Deserialization of untrusted data (CWE-502) occurs when an application deserializes untrusted data without sufficiently verifying that the resulting data will be valid, allowing the attacker to control the state or the flow of the execution.

com.fasterxml.jackson.core:jackson-databind allows deserialization of JSON input to Java objects. If an application using this dependency has the ability to deserialize a JSON string from an untrusted source, an attacker could leverage this vulnerability to conduct deserialization attacks.

Exploitation of unsafe deserialization attacks through jackson-databind requires the following prerequisites:

1. The target application allowing JSON user input which is processed by jackson-databind

An application using jackson-databind is only vulnerable if a user-provided JSON data is deserialized.

2. Polymorphic type handling for properties with nominal type are enabled

Polymorphic type handling refers to the addition of enough type information so that the deserializer can instantiate the appropriate subtype of a value. Use of "default typing" is considered dangerous due to the possibility of an untrusted method (gadget) managing to specify a class that is accessible through the class-loader and therefore, exposing a set of methods and/or fields.

3. An exploitable gadget class is available for the attacker to leverage

Gadget chains are specially crafted method sequences that can be created by an attacker in order to change the flow of code execution. These gadgets are often methods introduced by third-party components which an attacker could utilise in order to attack the target application. Not every gadget out there is supported by jackson-databind. The maintainers of jackson-databind proactively blacklists possible serialization gadgets in an attempt to ensure that it is not possible for an attacker to chain gadgets during serialization.

Further reading:

• On Jackson CVEs: Don’t Panic on Medium
• NCC Group Jackson Deserialization WhitePaper
• Java Security Best Practices

Remediation

Upgrade com.fasterxml.jackson.core:jackson-databind to version 2.9.10.8 or higher.

References

• GitHub Commit
• GitHub Issue
• Medium Article

Overview

com.fasterxml.jackson.core:jackson-databind is a library which contains the general-purpose data-binding functionality and tree-model for Jackson Data Processor.

Affected versions of this package are vulnerable to Deserialization of Untrusted Data. The package mishandles the interaction between serialization gadgets and typing, related to org.apache.tomcat.dbcp.dbcp2.datasources.PerUserPoolDataSource.

Details

Serialization is a process of converting an object into a sequence of bytes which can be persisted to a disk or database or can be sent through streams. The reverse process of creating objects from a sequence of bytes is called deserialization. Deserialization of untrusted data (CWE-502) occurs when an application deserializes untrusted data without sufficiently verifying that the resulting data will be valid, allowing the attacker to control the state or the flow of the execution.

com.fasterxml.jackson.core:jackson-databind allows deserialization of JSON input to Java objects. If an application using this dependency has the ability to deserialize a JSON string from an untrusted source, an attacker could leverage this vulnerability to conduct deserialization attacks.

Exploitation of unsafe deserialization attacks through jackson-databind requires the following prerequisites:

1. The target application allowing JSON user input which is processed by jackson-databind

An application using jackson-databind is only vulnerable if a user-provided JSON data is deserialized.

2. Polymorphic type handling for properties with nominal type are enabled

Polymorphic type handling refers to the addition of enough type information so that the deserializer can instantiate the appropriate subtype of a value. Use of "default typing" is considered dangerous due to the possibility of an untrusted method (gadget) managing to specify a class that is accessible through the class-loader and therefore, exposing a set of methods and/or fields.

3. An exploitable gadget class is available for the attacker to leverage

Gadget chains are specially crafted method sequences that can be created by an attacker in order to change the flow of code execution. These gadgets are often methods introduced by third-party components which an attacker could utilise in order to attack the target application. Not every gadget out there is supported by jackson-databind. The maintainers of jackson-databind proactively blacklists possible serialization gadgets in an attempt to ensure that it is not possible for an attacker to chain gadgets during serialization.

Further reading:

• On Jackson CVEs: Don’t Panic on Medium
• NCC Group Jackson Deserialization WhitePaper
• Java Security Best Practices

Remediation

Upgrade com.fasterxml.jackson.core:jackson-databind to version 2.9.10.8 or higher.

References

• GitHub Issue
• Medium Article
• PoC

Overview

com.fasterxml.jackson.core:jackson-databind is a library which contains the general-purpose data-binding functionality and tree-model for Jackson Data Processor.

Affected versions of this package are vulnerable to Deserialization of Untrusted Data. The package mishandles the interaction between serialization gadgets and typing, related to org.apache.tomcat.dbcp.dbcp.datasources.PerUserPoolDataSource.

Details

Serialization is a process of converting an object into a sequence of bytes which can be persisted to a disk or database or can be sent through streams. The reverse process of creating objects from a sequence of bytes is called deserialization. Deserialization of untrusted data (CWE-502) occurs when an application deserializes untrusted data without sufficiently verifying that the resulting data will be valid, allowing the attacker to control the state or the flow of the execution.

com.fasterxml.jackson.core:jackson-databind allows deserialization of JSON input to Java objects. If an application using this dependency has the ability to deserialize a JSON string from an untrusted source, an attacker could leverage this vulnerability to conduct deserialization attacks.

Exploitation of unsafe deserialization attacks through jackson-databind requires the following prerequisites:

1. The target application allowing JSON user input which is processed by jackson-databind

An application using jackson-databind is only vulnerable if a user-provided JSON data is deserialized.

2. Polymorphic type handling for properties with nominal type are enabled

Polymorphic type handling refers to the addition of enough type information so that the deserializer can instantiate the appropriate subtype of a value. Use of "default typing" is considered dangerous due to the possibility of an untrusted method (gadget) managing to specify a class that is accessible through the class-loader and therefore, exposing a set of methods and/or fields.

3. An exploitable gadget class is available for the attacker to leverage

Gadget chains are specially crafted method sequences that can be created by an attacker in order to change the flow of code execution. These gadgets are often methods introduced by third-party components which an attacker could utilise in order to attack the target application. Not every gadget out there is supported by jackson-databind. The maintainers of jackson-databind proactively blacklists possible serialization gadgets in an attempt to ensure that it is not possible for an attacker to chain gadgets during serialization.

Further reading:

• On Jackson CVEs: Don’t Panic on Medium
• NCC Group Jackson Deserialization WhitePaper
• Java Security Best Practices

Remediation

Upgrade com.fasterxml.jackson.core:jackson-databind to version 2.9.10.8 or higher.

References

• GitHub Issue
• Medium Article

Overview

com.fasterxml.jackson.core:jackson-databind is a library which contains the general-purpose data-binding functionality and tree-model for Jackson Data Processor.

Affected versions of this package are vulnerable to Deserialization of Untrusted Data. The package mishandles the interaction between serialization gadgets and typing, related to org.apache.commons.dbcp2.cpdsadapter.DriverAdapterCPDS.

Details

Serialization is a process of converting an object into a sequence of bytes which can be persisted to a disk or database or can be sent through streams. The reverse process of creating objects from a sequence of bytes is called deserialization. Deserialization of untrusted data (CWE-502) occurs when an application deserializes untrusted data without sufficiently verifying that the resulting data will be valid, allowing the attacker to control the state or the flow of the execution.

com.fasterxml.jackson.core:jackson-databind allows deserialization of JSON input to Java objects. If an application using this dependency has the ability to deserialize a JSON string from an untrusted source, an attacker could leverage this vulnerability to conduct deserialization attacks.

Exploitation of unsafe deserialization attacks through jackson-databind requires the following prerequisites:

1. The target application allowing JSON user input which is processed by jackson-databind

An application using jackson-databind is only vulnerable if a user-provided JSON data is deserialized.

2. Polymorphic type handling for properties with nominal type are enabled

Polymorphic type handling refers to the addition of enough type information so that the deserializer can instantiate the appropriate subtype of a value. Use of "default typing" is considered dangerous due to the possibility of an untrusted method (gadget) managing to specify a class that is accessible through the class-loader and therefore, exposing a set of methods and/or fields.

3. An exploitable gadget class is available for the attacker to leverage

Gadget chains are specially crafted method sequences that can be created by an attacker in order to change the flow of code execution. These gadgets are often methods introduced by third-party components which an attacker could utilise in order to attack the target application. Not every gadget out there is supported by jackson-databind. The maintainers of jackson-databind proactively blacklists possible serialization gadgets in an attempt to ensure that it is not possible for an attacker to chain gadgets during serialization.

Further reading:

• On Jackson CVEs: Don’t Panic on Medium
• NCC Group Jackson Deserialization WhitePaper
• Java Security Best Practices

Remediation

Upgrade com.fasterxml.jackson.core:jackson-databind to version 2.9.10.8 or higher.

References

• Al1ex's Poc
• GitHub Issue
• Medium Article

Overview

com.fasterxml.jackson.core:jackson-databind is a library which contains the general-purpose data-binding functionality and tree-model for Jackson Data Processor.

Affected versions of this package are vulnerable to Deserialization of Untrusted Data. The package mishandles the interaction between serialization gadgets and typing, related to org.docx4j.org.apache.xalan.lib.sql.JNDIConnectionPool.

Details

Serialization is a process of converting an object into a sequence of bytes which can be persisted to a disk or database or can be sent through streams. The reverse process of creating objects from a sequence of bytes is called deserialization. Deserialization of untrusted data (CWE-502) occurs when an application deserializes untrusted data without sufficiently verifying that the resulting data will be valid, allowing the attacker to control the state or the flow of the execution.

com.fasterxml.jackson.core:jackson-databind allows deserialization of JSON input to Java objects. If an application using this dependency has the ability to deserialize a JSON string from an untrusted source, an attacker could leverage this vulnerability to conduct deserialization attacks.

Exploitation of unsafe deserialization attacks through jackson-databind requires the following prerequisites:

1. The target application allowing JSON user input which is processed by jackson-databind

An application using jackson-databind is only vulnerable if a user-provided JSON data is deserialized.

2. Polymorphic type handling for properties with nominal type are enabled

Polymorphic type handling refers to the addition of enough type information so that the deserializer can instantiate the appropriate subtype of a value. Use of "default typing" is considered dangerous due to the possibility of an untrusted method (gadget) managing to specify a class that is accessible through the class-loader and therefore, exposing a set of methods and/or fields.

3. An exploitable gadget class is available for the attacker to leverage

Gadget chains are specially crafted method sequences that can be created by an attacker in order to change the flow of code execution. These gadgets are often methods introduced by third-party components which an attacker could utilise in order to attack the target application. Not every gadget out there is supported by jackson-databind. The maintainers of jackson-databind proactively blacklists possible serialization gadgets in an attempt to ensure that it is not possible for an attacker to chain gadgets during serialization.

Further reading:

• On Jackson CVEs: Don’t Panic on Medium
• NCC Group Jackson Deserialization WhitePaper
• Java Security Best Practices

Remediation

Upgrade com.fasterxml.jackson.core:jackson-databind to version 2.9.10.8 or higher.

References

• GitHub Issue
• Medium Article

Overview

com.fasterxml.jackson.core:jackson-databind is a library which contains the general-purpose data-binding functionality and tree-model for Jackson Data Processor.

Affected versions of this package are vulnerable to Deserialization of Untrusted Data. The package mishandles the interaction between serialization gadgets and typing, related to oadd.org.apache.commons.dbcp.cpdsadapter.DriverAdapterCPDS.

Details

Serialization is a process of converting an object into a sequence of bytes which can be persisted to a disk or database or can be sent through streams. The reverse process of creating objects from a sequence of bytes is called deserialization. Deserialization of untrusted data (CWE-502) occurs when an application deserializes untrusted data without sufficiently verifying that the resulting data will be valid, allowing the attacker to control the state or the flow of the execution.

com.fasterxml.jackson.core:jackson-databind allows deserialization of JSON input to Java objects. If an application using this dependency has the ability to deserialize a JSON string from an untrusted source, an attacker could leverage this vulnerability to conduct deserialization attacks.

Exploitation of unsafe deserialization attacks through jackson-databind requires the following prerequisites:

1. The target application allowing JSON user input which is processed by jackson-databind

An application using jackson-databind is only vulnerable if a user-provided JSON data is deserialized.

2. Polymorphic type handling for properties with nominal type are enabled

Polymorphic type handling refers to the addition of enough type information so that the deserializer can instantiate the appropriate subtype of a value. Use of "default typing" is considered dangerous due to the possibility of an untrusted method (gadget) managing to specify a class that is accessible through the class-loader and therefore, exposing a set of methods and/or fields.

3. An exploitable gadget class is available for the attacker to leverage

Gadget chains are specially crafted method sequences that can be created by an attacker in order to change the flow of code execution. These gadgets are often methods introduced by third-party components which an attacker could utilise in order to attack the target application. Not every gadget out there is supported by jackson-databind. The maintainers of jackson-databind proactively blacklists possible serialization gadgets in an attempt to ensure that it is not possible for an attacker to chain gadgets during serialization.

Further reading:

• On Jackson CVEs: Don’t Panic on Medium
• NCC Group Jackson Deserialization WhitePaper
• Java Security Best Practices

Remediation

Upgrade com.fasterxml.jackson.core:jackson-databind to version 2.9.10.8 or higher.

References

• Al1ex's Poc
• GitHub Issue
• Medium Article

Overview

com.fasterxml.jackson.core:jackson-databind is a library which contains the general-purpose data-binding functionality and tree-model for Jackson Data Processor.

Affected versions of this package are vulnerable to Deserialization of Untrusted Data. The package mishandles the interaction between serialization gadgets and typing, related to org.apache.tomcat.dbcp.dbcp2.cpdsadapter.DriverAdapterCPDS.

Details

Serialization is a process of converting an object into a sequence of bytes which can be persisted to a disk or database or can be sent through streams. The reverse process of creating objects from a sequence of bytes is called deserialization. Deserialization of untrusted data (CWE-502) occurs when an application deserializes untrusted data without sufficiently verifying that the resulting data will be valid, allowing the attacker to control the state or the flow of the execution.

com.fasterxml.jackson.core:jackson-databind allows deserialization of JSON input to Java objects. If an application using this dependency has the ability to deserialize a JSON string from an untrusted source, an attacker could leverage this vulnerability to conduct deserialization attacks.

Exploitation of unsafe deserialization attacks through jackson-databind requires the following prerequisites:

1. The target application allowing JSON user input which is processed by jackson-databind

An application using jackson-databind is only vulnerable if a user-provided JSON data is deserialized.

2. Polymorphic type handling for properties with nominal type are enabled

Polymorphic type handling refers to the addition of enough type information so that the deserializer can instantiate the appropriate subtype of a value. Use of "default typing" is considered dangerous due to the possibility of an untrusted method (gadget) managing to specify a class that is accessible through the class-loader and therefore, exposing a set of methods and/or fields.

3. An exploitable gadget class is available for the attacker to leverage

Gadget chains are specially crafted method sequences that can be created by an attacker in order to change the flow of code execution. These gadgets are often methods introduced by third-party components which an attacker could utilise in order to attack the target application. Not every gadget out there is supported by jackson-databind. The maintainers of jackson-databind proactively blacklists possible serialization gadgets in an attempt to ensure that it is not possible for an attacker to chain gadgets during serialization.

Further reading:

• On Jackson CVEs: Don’t Panic on Medium
• NCC Group Jackson Deserialization WhitePaper
• Java Security Best Practices

Remediation

Upgrade com.fasterxml.jackson.core:jackson-databind to version 2.9.10.8 or higher.

References

• GitHub Issue
• Medium Article
• PoC

Overview

com.fasterxml.jackson.core:jackson-databind is a library which contains the general-purpose data-binding functionality and tree-model for Jackson Data Processor.

Affected versions of this package are vulnerable to Deserialization of Untrusted Data. The package mishandles the interaction between serialization gadgets and typing, related to org.apache.tomcat.dbcp.dbcp2.datasources.SharedPoolDataSource.

Details

Serialization is a process of converting an object into a sequence of bytes which can be persisted to a disk or database or can be sent through streams. The reverse process of creating objects from a sequence of bytes is called deserialization. Deserialization of untrusted data (CWE-502) occurs when an application deserializes untrusted data without sufficiently verifying that the resulting data will be valid, allowing the attacker to control the state or the flow of the execution.

com.fasterxml.jackson.core:jackson-databind allows deserialization of JSON input to Java objects. If an application using this dependency has the ability to deserialize a JSON string from an untrusted source, an attacker could leverage this vulnerability to conduct deserialization attacks.

Exploitation of unsafe deserialization attacks through jackson-databind requires the following prerequisites:

1. The target application allowing JSON user input which is processed by jackson-databind

An application using jackson-databind is only vulnerable if a user-provided JSON data is deserialized.

2. Polymorphic type handling for properties with nominal type are enabled

Polymorphic type handling refers to the addition of enough type information so that the deserializer can instantiate the appropriate subtype of a value. Use of "default typing" is considered dangerous due to the possibility of an untrusted method (gadget) managing to specify a class that is accessible through the class-loader and therefore, exposing a set of methods and/or fields.

3. An exploitable gadget class is available for the attacker to leverage

Gadget chains are specially crafted method sequences that can be created by an attacker in order to change the flow of code execution. These gadgets are often methods introduced by third-party components which an attacker could utilise in order to attack the target application. Not every gadget out there is supported by jackson-databind. The maintainers of jackson-databind proactively blacklists possible serialization gadgets in an attempt to ensure that it is not possible for an attacker to chain gadgets during serialization.

Further reading:

• On Jackson CVEs: Don’t Panic on Medium
• NCC Group Jackson Deserialization WhitePaper
• Java Security Best Practices

Remediation

Upgrade com.fasterxml.jackson.core:jackson-databind to version 2.9.10.8 or higher.

References

• GitHub Issue
• Medium Article

Overview

com.fasterxml.jackson.core:jackson-databind is a library which contains the general-purpose data-binding functionality and tree-model for Jackson Data Processor.

Affected versions of this package are vulnerable to Deserialization of Untrusted Data. The package mishandles the interaction between serialization gadgets and typing, related to com.newrelic.agent.deps.ch.qos.logback.core.db.DriverManagerConnectionSource.

Details

Serialization is a process of converting an object into a sequence of bytes which can be persisted to a disk or database or can be sent through streams. The reverse process of creating objects from a sequence of bytes is called deserialization. Deserialization of untrusted data (CWE-502) occurs when an application deserializes untrusted data without sufficiently verifying that the resulting data will be valid, allowing the attacker to control the state or the flow of the execution.

com.fasterxml.jackson.core:jackson-databind allows deserialization of JSON input to Java objects. If an application using this dependency has the ability to deserialize a JSON string from an untrusted source, an attacker could leverage this vulnerability to conduct deserialization attacks.

Exploitation of unsafe deserialization attacks through jackson-databind requires the following prerequisites:

1. The target application allowing JSON user input which is processed by jackson-databind

An application using jackson-databind is only vulnerable if a user-provided JSON data is deserialized.

2. Polymorphic type handling for properties with nominal type are enabled

Polymorphic type handling refers to the addition of enough type information so that the deserializer can instantiate the appropriate subtype of a value. Use of "default typing" is considered dangerous due to the possibility of an untrusted method (gadget) managing to specify a class that is accessible through the class-loader and therefore, exposing a set of methods and/or fields.

3. An exploitable gadget class is available for the attacker to leverage

Gadget chains are specially crafted method sequences that can be created by an attacker in order to change the flow of code execution. These gadgets are often methods introduced by third-party components which an attacker could utilise in order to attack the target application. Not every gadget out there is supported by jackson-databind. The maintainers of jackson-databind proactively blacklists possible serialization gadgets in an attempt to ensure that it is not possible for an attacker to chain gadgets during serialization.

Further reading:

• On Jackson CVEs: Don’t Panic on Medium
• NCC Group Jackson Deserialization WhitePaper
• Java Security Best Practices

Remediation

Upgrade com.fasterxml.jackson.core:jackson-databind to version 2.9.10.8 or higher.

References

• GitHub Issue
• Medium Article

Overview

com.fasterxml.jackson.core:jackson-databind is a library which contains the general-purpose data-binding functionality and tree-model for Jackson Data Processor.

Affected versions of this package are vulnerable to Deserialization of Untrusted Data. The package mishandles the interaction between serialization gadgets and typing, related to com.newrelic.agent.deps.ch.qos.logback.core.db.JNDIConnectionSource.

Details

Serialization is a process of converting an object into a sequence of bytes which can be persisted to a disk or database or can be sent through streams. The reverse process of creating objects from a sequence of bytes is called deserialization. Deserialization of untrusted data (CWE-502) occurs when an application deserializes untrusted data without sufficiently verifying that the resulting data will be valid, allowing the attacker to control the state or the flow of the execution.

com.fasterxml.jackson.core:jackson-databind allows deserialization of JSON input to Java objects. If an application using this dependency has the ability to deserialize a JSON string from an untrusted source, an attacker could leverage this vulnerability to conduct deserialization attacks.

Exploitation of unsafe deserialization attacks through jackson-databind requires the following prerequisites:

1. The target application allowing JSON user input which is processed by jackson-databind

An application using jackson-databind is only vulnerable if a user-provided JSON data is deserialized.

2. Polymorphic type handling for properties with nominal type are enabled

Polymorphic type handling refers to the addition of enough type information so that the deserializer can instantiate the appropriate subtype of a value. Use of "default typing" is considered dangerous due to the possibility of an untrusted method (gadget) managing to specify a class that is accessible through the class-loader and therefore, exposing a set of methods and/or fields.

3. An exploitable gadget class is available for the attacker to leverage

Gadget chains are specially crafted method sequences that can be created by an attacker in order to change the flow of code execution. These gadgets are often methods introduced by third-party components which an attacker could utilise in order to attack the target application. Not every gadget out there is supported by jackson-databind. The maintainers of jackson-databind proactively blacklists possible serialization gadgets in an attempt to ensure that it is not possible for an attacker to chain gadgets during serialization.

Further reading:

• On Jackson CVEs: Don’t Panic on Medium
• NCC Group Jackson Deserialization WhitePaper
• Java Security Best Practices

Remediation

Upgrade com.fasterxml.jackson.core:jackson-databind to version 2.9.10.8 or higher.

References

• GitHub Issue
• Medium Article
• PoC

Overview

com.fasterxml.jackson.core:jackson-databind is a library which contains the general-purpose data-binding functionality and tree-model for Jackson Data Processor.

Affected versions of this package are vulnerable to Deserialization of Untrusted Data. The package mishandles the interaction between serialization gadgets and typing, related to org.apache.tomcat.dbcp.dbcp.cpdsadapter.DriverAdapterCPDS.

Details

Serialization is a process of converting an object into a sequence of bytes which can be persisted to a disk or database or can be sent through streams. The reverse process of creating objects from a sequence of bytes is called deserialization. Deserialization of untrusted data (CWE-502) occurs when an application deserializes untrusted data without sufficiently verifying that the resulting data will be valid, allowing the attacker to control the state or the flow of the execution.

com.fasterxml.jackson.core:jackson-databind allows deserialization of JSON input to Java objects. If an application using this dependency has the ability to deserialize a JSON string from an untrusted source, an attacker could leverage this vulnerability to conduct deserialization attacks.

Exploitation of unsafe deserialization attacks through jackson-databind requires the following prerequisites:

1. The target application allowing JSON user input which is processed by jackson-databind

An application using jackson-databind is only vulnerable if a user-provided JSON data is deserialized.

2. Polymorphic type handling for properties with nominal type are enabled

Polymorphic type handling refers to the addition of enough type information so that the deserializer can instantiate the appropriate subtype of a value. Use of "default typing" is considered dangerous due to the possibility of an untrusted method (gadget) managing to specify a class that is accessible through the class-loader and therefore, exposing a set of methods and/or fields.

3. An exploitable gadget class is available for the attacker to leverage

Gadget chains are specially crafted method sequences that can be created by an attacker in order to change the flow of code execution. These gadgets are often methods introduced by third-party components which an attacker could utilise in order to attack the target application. Not every gadget out there is supported by jackson-databind. The maintainers of jackson-databind proactively blacklists possible serialization gadgets in an attempt to ensure that it is not possible for an attacker to chain gadgets during serialization.

Further reading:

• On Jackson CVEs: Don’t Panic on Medium
• NCC Group Jackson Deserialization WhitePaper
• Java Security Best Practices

Remediation

Upgrade com.fasterxml.jackson.core:jackson-databind to version 2.9.10.8 or higher.

References

• GitHub Issue
• Medium Article
• Poc

Overview

com.fasterxml.jackson.core:jackson-databind is a library which contains the general-purpose data-binding functionality and tree-model for Jackson Data Processor.

Affected versions of this package are vulnerable to Deserialization of Untrusted Data. A malicious user could perform a SSRF attack via the javax.swing gadget (specifically javax.swing.JTextPane).

Details

Serialization is a process of converting an object into a sequence of bytes which can be persisted to a disk or database or can be sent through streams. The reverse process of creating object from sequence of bytes is called deserialization. Serialization is commonly used for communication (sharing objects between multiple hosts) and persistence (store the object state in a file or a database). It is an integral part of popular protocols like Remote Method Invocation (RMI), Java Management Extension (JMX), Java Messaging System (JMS), Action Message Format (AMF), Java Server Faces (JSF) ViewState, etc.

Deserialization of untrusted data (CWE-502), is when the application deserializes untrusted data without sufficiently verifying that the resulting data will be valid, letting the attacker to control the state or the flow of the execution.

Java deserialization issues have been known for years. However, interest in the issue intensified greatly in 2015, when classes that could be abused to achieve remote code execution were found in a popular library (Apache Commons Collection). These classes were used in zero-days affecting IBM WebSphere, Oracle WebLogic and many other products.

An attacker just needs to identify a piece of software that has both a vulnerable class on its path, and performs deserialization on untrusted data. Then all they need to do is send the payload into the deserializer, getting the command executed.

Developers put too much trust in Java Object Serialization. Some even de-serialize objects pre-authentication. When deserializing an Object in Java you typically cast it to an expected type, and therefore Java's strict type system will ensure you only get valid object trees. Unfortunately, by the time the type checking happens, platform code has already created and executed significant logic. So, before the final type is checked a lot of code is executed from the readObject() methods of various objects, all of which is out of the developer's control. By combining the readObject() methods of various classes which are available on the classpath of the vulnerable application, an attacker can execute functions (including calling Runtime.exec() to execute local OS commands).

Remediation

Upgrade com.fasterxml.jackson.core:jackson-databind to version 2.9.10.7 or higher.

References

• GitHub Commit
• GitHub Issue
• GitHub Release
• RedHat Bugzilla Bug

Overview

log4j:log4j is a 1.x branch of the Apache Log4j project.

Affected versions of this package are vulnerable to Deserialization of Untrusted Data. CVE-2020-9493 identified a deserialization issue that was present in Apache Chainsaw. Prior to Chainsaw V2.0 Chainsaw was a component of Apache Log4j 1.2.x where the same issue exists.

Details

Serialization is a process of converting an object into a sequence of bytes which can be persisted to a disk or database or can be sent through streams. The reverse process of creating object from sequence of bytes is called deserialization. Serialization is commonly used for communication (sharing objects between multiple hosts) and persistence (store the object state in a file or a database). It is an integral part of popular protocols like Remote Method Invocation (RMI), Java Management Extension (JMX), Java Messaging System (JMS), Action Message Format (AMF), Java Server Faces (JSF) ViewState, etc.

Deserialization of untrusted data (CWE-502) is when the application deserializes untrusted data without sufficiently verifying that the resulting data will be valid, thus allowing the attacker to control the state or the flow of the execution.

Remediation

There is no fixed version for log4j:log4j.

References

• Apache Mailing List
• Apache Security Advisory
• Atlassian Patch
• Reload4j Fix Commit

Overview

log4j:log4j is a 1.x branch of the Apache Log4j project.

Affected versions of this package are vulnerable to Deserialization of Untrusted Data. JMSSink in all versions of Log4j 1.x is vulnerable to deserialization of untrusted data when the attacker has write access to the Log4j configuration or if the configuration references an LDAP service the attacker has access to. The attacker can provide a TopicConnectionFactoryBindingName configuration causing JMSSink to perform JNDI requests that result in remote code execution in a similar fashion to CVE-2021-4104.

Note: this issue only affects Log4j 1.x when specifically configured to use JMSSink, which is not the default.

Apache Log4j 1.2 reached end of life in August 2015. Users should upgrade to Log4j 2 as it addresses numerous other issues from the previous versions.

Details

Serialization is a process of converting an object into a sequence of bytes which can be persisted to a disk or database or can be sent through streams. The reverse process of creating object from sequence of bytes is called deserialization. Serialization is commonly used for communication (sharing objects between multiple hosts) and persistence (store the object state in a file or a database). It is an integral part of popular protocols like Remote Method Invocation (RMI), Java Management Extension (JMX), Java Messaging System (JMS), Action Message Format (AMF), Java Server Faces (JSF) ViewState, etc.

Deserialization of untrusted data (CWE-502) is when the application deserializes untrusted data without sufficiently verifying that the resulting data will be valid, thus allowing the attacker to control the state or the flow of the execution.

Remediation

There is no fixed version for log4j:log4j.

References

• Apache Mailing List
• Apache Security Advisory
• Atlassian Patch
• Reload4j Fix Commit

Overview

log4j:log4j is a 1.x branch of the Apache Log4j project.

Affected versions of this package are vulnerable to SQL Injection. By design, the JDBCAppender in Log4j 1.2.x accepts an SQL statement as a configuration parameter where the values to be inserted are converters from PatternLayout. The message converter, %m, is likely to always be included. This allows attackers to manipulate the SQL by entering crafted strings into input fields or headers of an application that are logged allowing unintended SQL queries to be executed.

Note: this issue only affects Log4j 1.x when specifically configured to use the JDBCAppender, which is not the default.

Apache Log4j 1.2 reached end of life in August 2015. Users should upgrade to Log4j 2 as it addresses numerous other issues from the previous versions. Beginning in version 2.0-beta8, the JDBCAppender was re-introduced with proper support for parameterized SQL queries and further customization over the columns written to in logs.

Remediation

There is no fixed version for log4j:log4j.

References

• Apache Mailing List
• Apache Security Advisory
• Atlassian Patch
• Reload4j Fix Commit

Overview

com.fasterxml.jackson.core:jackson-databind is a library which contains the general-purpose data-binding functionality and tree-model for Jackson Data Processor.

Affected versions of this package are vulnerable to Denial of Service (DoS) via a large depth of nested objects.

Details

Denial of Service (DoS) describes a family of attacks, all aimed at making a system inaccessible to its intended and legitimate users.

Unlike other vulnerabilities, DoS attacks usually do not aim at breaching security. Rather, they are focused on making websites and services unavailable to genuine users resulting in downtime.

One popular Denial of Service vulnerability is DDoS (a Distributed Denial of Service), an attack that attempts to clog network pipes to the system by generating a large volume of traffic from many machines.

When it comes to open source libraries, DoS vulnerabilities allow attackers to trigger such a crash or crippling of the service by using a flaw either in the application code or from the use of open source libraries.

Two common types of DoS vulnerabilities:

• High CPU/Memory Consumption- An attacker sending crafted requests that could cause the system to take a disproportionate amount of time to process. For example, commons-fileupload:commons-fileupload.

• Crash - An attacker sending crafted requests that could cause the system to crash. For Example, npm ws package

Remediation

Upgrade com.fasterxml.jackson.core:jackson-databind to version 2.12.6.1, 2.13.2.1 or higher.

References

• GitHub Commit
• GitHub Commit
• GitHub Issue
• GitHub PR