Find, fix and prevent vulnerabilities in your code.

Overview

org.apache.logging.log4j:log4j-core is a logging library for Java.

Affected versions of this package are vulnerable to Arbitrary Code Execution.
Note: Even though this vulnerability appears to be related to the log4Shell vulnerability, this vulnerability requires an attacker to have access to modify configurations to be exploitable, which is rarely possible.

An attacker with access to modification of logging configuration is able to configure JDBCAppender with a data source referencing a JNDI URI - which can execute malicious code.

In the fixed versions, JDBCAppender is using JndiManager and disables JNDI lookups by default (via log4j2.enableJndiJdbc=false).

Alternative Remediation

If you have reason to believe your application may be vulnerable and upgrading is not an option, you can either:

• Disable/remove JDBCAppender
• If JDBCAppender is used, make sure that it is not configured to use any protocol other than Java

Remediation

Upgrade org.apache.logging.log4j:log4j-core to version 2.3.2, 2.12.4, 2.17.1 or higher.

References

• Apache Security Page
• GitHub Commit
• Jira Issue
• Openwall Mail

Overview

org.apache.logging.log4j:log4j-core is a logging library for Java.

Affected versions of this package are vulnerable to Improper Validation of Certificate with Host Mismatch due to the lack of TLS hostname verification in the SocketAppender component. An attacker can intercept or redirect log traffic by performing a man-in-the-middle attack if they are able to intercept or redirect network traffic between the client and the log receiver and can present a server certificate issued by a certification authority trusted by the configured trust store or the default Java trust store.

Workaround

This vulnerability can be mitigated by configuring the SocketAppender to use a private or restricted trust root to limit the set of trusted certificates.

Remediation

Upgrade org.apache.logging.log4j:log4j-core to version 2.25.3 or higher.

References

• Apache Advisory
• Apache Documentation
• Apache Documentation
• Apache Thread
• GitHub Commit
• GitHub PR

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) when using JDK serialization to serialize and deserialize JsonNode values. It is possible for the attacker to send a 4-byte length payload, with a value of Integer.MAX_VALUE , that will eventually cause large buffer allocation and out of heap memory.

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 2.13.1, 2.12.6 or higher.

References

• GitHub Commit
• 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 Denial of Service (DoS) in the _deserializeFromArray() function in BeanDeserializer, due to resource exhaustion when processing a deeply nested array.

NOTE: For this vulnerability to be exploitable the non-default DeserializationFeature must be enabled.

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 2.12.7.1, 2.13.4 or higher.

References

• Chromium Bugs
• GitHub Commit
• GitHub Commit
• 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 Denial of Service (DoS) in the _deserializeWrappedValue() function in StdDeserializer.java, due to resource exhaustion when processing deeply nested arrays.

NOTE: This vulnerability is only exploitable when the non-default UNWRAP_SINGLE_VALUE_ARRAYS feature is enabled.

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 2.12.7.1, 2.13.4.1 or higher.

References

• Chromium Bugs
• Documentation
• GitHub Commit
• GitHub Commit
• GitHub Commit
• GitHub Issue

Overview

com.fasterxml.jackson.core:jackson-core is a Core Jackson abstractions, basic JSON streaming API implementation

Affected versions of this package are vulnerable to Information Exposure due to the JsonLocation._appendSourceDesc method. An attacker can access up to 500 bytes of unintended memory content by exploiting exception messages that incorrectly read from the beginning of a byte array instead of the logical payload start.

Workaround

This vulnerability can be mitigated by disabling exception message exposure to clients to avoid returning parsing exception messages in HTTP responses and/or disabling source inclusion in exceptions to prevent Jackson from embedding any source content in exception messages, avoiding leakage.

PoC

byte[] buffer = new byte[1000];
System.arraycopy("SECRET".getBytes(), 0, buffer, 0, 6);
System.arraycopy("{ \"bad\": }".getBytes(), 0, buffer, 700, 10);

JsonFactory factory = new JsonFactory();
JsonParser parser = factory.createParser(buffer, 700, 20);
parser.nextToken(); // throws exception

// Exception message will include "SECRET"

Remediation

Upgrade com.fasterxml.jackson.core:jackson-core to version 2.13.0-rc1 or higher.

References

• GitHub Commit
• GitHub PR

EPL-1.0 license