Find, fix and prevent vulnerabilities in your code.

Overview

Affected versions of this package are vulnerable to Memory Allocation with Excessive Size Value through the LZ4DecompressorWithLength.decompress process. An attacker can cause excessive memory allocation and trigger a denial of service by supplying a crafted input with a manipulated length header.

Remediation

Upgrade at.yawk.lz4:lz4-java to version 1.11.2 or higher.

References

• GitHub Advisory
• GitHub Commit

Overview

Affected versions of this package are vulnerable to Memory Allocation with Excessive Size Value via the LZ4BlockInputStream process. An attacker can cause excessive memory allocation and exhaust system resources by supplying a crafted legacy LZ4Block stream with a large compressedLen value in the stream header.

Remediation

Upgrade at.yawk.lz4:lz4-java to version 1.11.2 or higher.

References

• GitHub Advisory
• GitHub Commit
• GitHub Release

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 Regular Expression Denial of Service (ReDoS) in the PATTERN_FLOAT regex of NumberInput, reached through looksLikeValidNumber(), where adjacent quantifiers over the same character class ([0-9]*, then an optional [.], then [0-9]+) carry no possessive quantifiers or atomic grouping, so the engine explores every split point between digit groups on non-matching input. An attacker can pin a request-handling thread and exhaust the worker pool with concurrent requests by supplying a long numeric-looking string that fails to match, since match cost is quadratic in input length, with 160,000 characters costing 74.4 seconds in a single call. This requires the application to reach looksLikeValidNumber() with attacker-controlled strings, which is the default path when jackson-databind coerces a String field to a number, and the input is bounded only by StreamReadConstraints.maxStringLength at 20,000,000 rather than by maxNumberLength at 1,000.

Workaround

This vulnerability can be avoided by lowering StreamReadConstraints.maxStringLength toward the string length the application actually needs, which caps the input this quadratic path can be handed, since it is that limit and not maxNumberLength that governs here.

Details

Denial of Service (DoS) describes a family of attacks, all aimed at making a system inaccessible to its original and legitimate users. There are many types of DoS attacks, ranging from trying to clog the network pipes to the system by generating a large volume of traffic from many machines (a Distributed Denial of Service - DDoS - attack) to sending crafted requests that cause a system to crash or take a disproportional amount of time to process.

The Regular expression Denial of Service (ReDoS) is a type of Denial of Service attack. Regular expressions are incredibly powerful, but they aren't very intuitive and can ultimately end up making it easy for attackers to take your site down.

Let’s take the following regular expression as an example:

regex = /A(B|C+)+D/

This regular expression accomplishes the following:

• A The string must start with the letter 'A'
• (B|C+)+ The string must then follow the letter A with either the letter 'B' or some number of occurrences of the letter 'C' (the + matches one or more times). The + at the end of this section states that we can look for one or more matches of this section.
• D Finally, we ensure this section of the string ends with a 'D'

The expression would match inputs such as ABBD, ABCCCCD, ABCBCCCD and ACCCCCD

It most cases, it doesn't take very long for a regex engine to find a match:

$ time node -e '/A(B|C+)+D/.test("ACCCCCCCCCCCCCCCCCCCCCCCCCCCCD")'
0.04s user 0.01s system 95% cpu 0.052 total

$ time node -e '/A(B|C+)+D/.test("ACCCCCCCCCCCCCCCCCCCCCCCCCCCCX")'
1.79s user 0.02s system 99% cpu 1.812 total

The entire process of testing it against a 30 characters long string takes around ~52ms. But when given an invalid string, it takes nearly two seconds to complete the test, over ten times as long as it took to test a valid string. The dramatic difference is due to the way regular expressions get evaluated.

Most Regex engines will work very similarly (with minor differences). The engine will match the first possible way to accept the current character and proceed to the next one. If it then fails to match the next one, it will backtrack and see if there was another way to digest the previous character. If it goes too far down the rabbit hole only to find out the string doesn’t match in the end, and if many characters have multiple valid regex paths, the number of backtracking steps can become very large, resulting in what is known as catastrophic backtracking.

Let's look at how our expression runs into this problem, using a shorter string: "ACCCX". While it seems fairly straightforward, there are still four different ways that the engine could match those three C's:

1. CCC
2. CC+C
3. C+CC
4. C+C+C.

The engine has to try each of those combinations to see if any of them potentially match against the expression. When you combine that with the other steps the engine must take, we can use RegEx 101 debugger to see the engine has to take a total of 38 steps before it can determine the string doesn't match.

From there, the number of steps the engine must use to validate a string just continues to grow.

By the time the string includes 14 C's, the engine has to take over 65,000 steps just to see if the string is valid. These extreme situations can cause them to work very slowly (exponentially related to input size, as shown above), allowing an attacker to exploit this and can cause the service to excessively consume CPU, resulting in a Denial of Service.

Remediation

Upgrade com.fasterxml.jackson.core:jackson-core to version 2.18.11, 2.21.7, 2.22.3 or higher.

References

• GitHub Advisory
• GitHub Commit
• GitHub Commit
• GitHub Issue
• GitHub PR
• 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 Allocation of Resources Without Limits or Throttling in the _findDeserializer() method of TypeDeserializerBase, which caches every unknown type ID as a distinct key in the _deserializers map even when all of them resolve to the same defaultImpl fallback. An attacker can grow that cache without bound for the lifetime of the process, exhausting memory over time, by submitting a stream of novel type identifiers. This requires the application to use name-based polymorphism through @JsonTypeInfo(use = Id.NAME, defaultImpl = ...), to accept attacker-controlled type identifiers, and to reuse the mapper instance across requests.

Remediation

Upgrade com.fasterxml.jackson.core:jackson-databind to version 2.18.11, 2.21.7, 2.22.3 or higher.

References

• GitHub Advisory
• 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 Improperly Controlled Modification of Dynamically-Determined Object Attributes in the POJOPropertiesCollector._renameProperties() and BeanDeserializerFactory.addBeanProps() methods, which rename rather than drop a property whose getter carries @JsonProperty and whose setter carries @JsonIgnore, leaving the private backing field writable. An attacker can write a field that was meant to be unsettable, enabling property tampering and mass assignment, by supplying the renamed JSON key during deserialization, because the factory observes hasField()==true and builds a writable FieldProperty for the backing field. Exploitation requires MapperFeature.INFER_PROPERTY_MUTATORS to be enabled, which is the default, and a target type that pairs a renamed getter with an ignored setter, and the impact is limited to writing existing fields with no path to remote code execution.

Remediation

Upgrade com.fasterxml.jackson.core:jackson-databind to version 2.21.4 or higher.

References

• GitHub Advisory
• GitHub Commit
• GitHub Commit
• GitHub PR
• 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 Improperly Controlled Modification of Dynamically-Determined Object Attributes in the BeanDeserializerBase.createContextual() method, which applies the per-property exclusions through _handleByNameInclusion() and then rebuilds the property map from the unfiltered original, overwriting the filtered map and restoring every property the exclusion had removed. An attacker can set fields that were marked ignored, enabling mass assignment, by supplying those property names in untrusted JSON during deserialization. Exploitation requires case-insensitive property matching to be enabled via @JsonFormat with ACCEPT_CASE_INSENSITIVE_PROPERTIES alongside per-property @JsonIgnoreProperties.

Remediation

Upgrade com.fasterxml.jackson.core:jackson-databind to version 2.18.9, 2.21.5, 2.22.1 or higher.

References

• GitHub Advisory
• GitHub Commit
• GitHub Issue
• 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 Improperly Controlled Modification of Dynamically-Determined Object Attributes in the POJOPropertiesCollector._removeUnwantedIgnorals process. An attacker can access or modify properties that were intended to be ignored by supplying JSON input with keys matching the renamed property names, thereby bypassing intended access restrictions.

Remediation

Upgrade com.fasterxml.jackson.core:jackson-databind to version 2.18.8, 2.21.4 or higher.

References

• GitHub Advisory
• GitHub Commit
• 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 Server-side Request Forgery (SSRF) in the JDKFromStringDeserializer class, which constructs InetSocketAddress and resolves the hostname through DNS at deserialization time. An attacker can force the server to issue outbound DNS lookups for chosen hostnames by submitting JSON that is deserialized into a type holding an InetSocketAddress field, with no authentication required. The observable effect is limited to DNS resolution of attacker-chosen names, useful for out-of-band interaction or internal resolver probing rather than a full outbound request, and it applies only where the application deserializes untrusted JSON into types containing such fields.

Remediation

Upgrade com.fasterxml.jackson.core:jackson-databind to version 2.18.8, 2.21.4 or higher.

References

• GitHub Advisory
• 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 Server-side Request Forgery (SSRF) through the STD_INET_ADDRESS branch in FromStringDeserializer in src/main/java/com/fasterxml/jackson/databind/deser/std/FromStringDeserializer.java. An attacker can trigger outbound DNS lookups and blind SSRF behavior by supplying a hostname string in JSON that is deserialized into java.net.InetAddress. When application code binds untrusted input into an InetAddress field or type, the deserializer calls InetAddress.getByName(value) on the attacker-controlled string and resolves it before any application validation runs. This lets an attacker force DNS-based callbacks or probe internal hostnames, causing unwanted network egress and leaking resolver-visible information.

Remediation

Upgrade com.fasterxml.jackson.core:jackson-databind to version 2.18.9, 2.21.5, 2.22.1 or higher.

References

• GitHub Commit jackson-databind-2.21.1
• GitHub Commit jackson-databind-3.2.1
• Maintainer's Advisory

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 Use of Externally-Controlled Input to Select Classes or Code ('Unsafe Reflection') through NioPathDeserializer in src/main/java/com/fasterxml/jackson/databind/ext/NioPathDeserializer.java. An attacker can force readValue() to resolve an attacker-controlled java.nio.file.Path URI by supplying a non-file scheme such as jar:, http:, s3:, or a custom provider scheme in untrusted JSON. That input reaches new URI(value) and then Path.of(uri), which falls back to ServiceLoader<FileSystemProvider> resolution and can invoke a matching provider’s getPath(uri) during deserialization. The result is unintended provider loading and provider-driven path handling inside the application, which can trigger denial of service or other side effects depending on what FileSystemProvider implementations are present on the classpath.

Remediation

Upgrade com.fasterxml.jackson.core:jackson-databind to version 2.18.10, 2.21.6, 2.22.2 or higher.

References

• GitHub Commit
• GitHub Commit
• GitHub Commit
• GitHub PR
• Maintainer's Advisory

Overview

org.lz4:lz4-java is a Java port of the LZ4 compression algorithm and the xxHash hashing algorithm.

Affected versions of this package are vulnerable to Memory Allocation with Excessive Size Value through the LZ4DecompressorWithLength.decompress process. An attacker can cause excessive memory allocation and trigger a denial of service by supplying a crafted input with a manipulated length header.

Remediation

There is no fixed version for org.lz4:lz4-java.

References

• GitHub Advisory
• GitHub Commit

Overview

org.lz4:lz4-java is a Java port of the LZ4 compression algorithm and the xxHash hashing algorithm.

Affected versions of this package are vulnerable to Memory Allocation with Excessive Size Value via the LZ4BlockInputStream process. An attacker can cause excessive memory allocation and exhaust system resources by supplying a crafted legacy LZ4Block stream with a large compressedLen value in the stream header.

Remediation

There is no fixed version for org.lz4:lz4-java.

References

• GitHub Advisory
• GitHub Commit
• GitHub Release

Overview

Affected versions of this package are vulnerable to Out-of-bounds Write through the Snappy.uncompress*Array methods. An attacker can corrupt heap memory and potentially cause application crashes or unexpected behavior by supplying specially crafted compressed input that results in misaligned length values, leading to writes past array bounds.

Remediation

Upgrade org.xerial.snappy:snappy-java to version 1.1.10.9 or higher.

References

• GitHub Commit
• GitHub Issue
• GitHub PR
• Vulnerable Code

Overview

Affected versions of this package are vulnerable to Uncontrolled Recursion in the refill function when processing LZ4 block streams with stopOnEmptyBlock set to false. An attacker can cause a thread to terminate unexpectedly by providing a stream with a large number of consecutive empty blocks, leading to stack exhaustion and application unavailability. This is only exploitable if the configuration option stopOnEmptyBlock is explicitly set to false.

Remediation

Upgrade at.yawk.lz4:lz4-java to version 1.11.4 or higher.

References

• GitHub Advisory
• GitHub Commit
• GitHub Release

Overview

ch.qos.logback:logback-classic is a reliable, generic, fast and flexible logging library for Java.

Affected versions of this package are vulnerable to Deserialization of Untrusted Data in HardenedObjectInputStream, whose resolveClass allowlist admitted any class whose name starts with java.lang or java.util rather than matching specific authorized classes. An attacker can instantiate dangerous classes such as java.lang.ProcessBuilder during deserialization, reaching remote code execution through a gadget chain, by delivering a malicious serialized object to a logback component that deserializes it, such as its socket receiver for serialized logging events (SocketNode). Exploitation requires the application to deserialize attacker-controlled serialized data through logback, in practice via its socket-based receiver, together with a usable gadget class on the classpath.

Workaround

This vulnerability can be avoided by not exposing logback's socket-based serialized receivers, such as SocketReceiver and ServerSocketReceiver, to untrusted networks, which removes the path by which attacker-controlled serialized objects reach the deserialization filter.

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

Upgrade ch.qos.logback:logback-classic to version 1.5.33 or higher.

References

• Apache Jira Issues
• GitHub Commit
• Release Notes

Overview

ch.qos.logback:logback-classic is a reliable, generic, fast and flexible logging library for Java.

Affected versions of this package are vulnerable to Directory Traversal via unsanitized input in the MDCDiscriminator process. An attacker can create or append log files outside the intended directory by supplying crafted values, such as through HTTP headers, that influence the log file path. This is only exploitable if SiftingAppender is active and unsanitized data is used by MDCDiscriminator.

Workaround

This vulnerability can be mitigated by sanitizing relevant data provided by the user.

Details

A Directory Traversal attack (also known as path traversal) aims to access files and directories that are stored outside the intended folder. By manipulating files with "dot-dot-slash (../)" sequences and its variations, or by using absolute file paths, it may be possible to access arbitrary files and directories stored on file system, including application source code, configuration, and other critical system files.

Directory Traversal vulnerabilities can be generally divided into two types:

• Information Disclosure: Allows the attacker to gain information about the folder structure or read the contents of sensitive files on the system.

st is a module for serving static files on web pages, and contains a vulnerability of this type. In our example, we will serve files from the public route.

If an attacker requests the following URL from our server, it will in turn leak the sensitive private key of the root user.

curl http://localhost:8080/public/%2e%2e/%2e%2e/%2e%2e/%2e%2e/%2e%2e/root/.ssh/id_rsa

Note %2e is the URL encoded version of . (dot).

• Writing arbitrary files: Allows the attacker to create or replace existing files. This type of vulnerability is also known as Zip-Slip.

One way to achieve this is by using a malicious zip archive that holds path traversal filenames. When each filename in the zip archive gets concatenated to the target extraction folder, without validation, the final path ends up outside of the target folder. If an executable or a configuration file is overwritten with a file containing malicious code, the problem can turn into an arbitrary code execution issue quite easily.

The following is an example of a zip archive with one benign file and one malicious file. Extracting the malicious file will result in traversing out of the target folder, ending up in /root/.ssh/ overwriting the authorized_keys file:

2018-04-15 22:04:29 .....           19           19  good.txt
2018-04-15 22:04:42 .....           20           20  ../../../../../../root/.ssh/authorized_keys

Remediation

Upgrade ch.qos.logback:logback-classic to version 1.6.5 or higher.

References

• GitHub Release
• logback.qos.ch

Overview

ch.qos.logback:logback-core is a logback-core module.

Affected versions of this package are vulnerable to Deserialization of Untrusted Data in the HardenedObjectInputStream module. An attacker can instantiate unauthorized Proxy objects by supplying crafted serialized data to the SimpleSocketServer or SimpleSSLSocketServer, thereby bypassing intended security restrictions.

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

Upgrade ch.qos.logback:logback-core to version 1.5.34 or higher.

References

• GitHub Commit
• Logback Release Notes

Overview

ch.qos.logback:logback-core is a logback-core module.

Affected versions of this package are vulnerable to Deserialization of Untrusted Data in HardenedObjectInputStream, whose resolveClass allowlist admitted any class whose name starts with java.lang or java.util rather than matching specific authorized classes. An attacker can instantiate dangerous classes such as java.lang.ProcessBuilder during deserialization, reaching remote code execution through a gadget chain, by delivering a malicious serialized object to a logback component that deserializes it, such as its socket receiver for serialized logging events (SocketNode). Exploitation requires the application to deserialize attacker-controlled serialized data through logback, in practice via its socket-based receiver, together with a usable gadget class on the classpath.

Workaround

This vulnerability can be avoided by not exposing logback's socket-based serialized receivers, such as SocketReceiver and ServerSocketReceiver, to untrusted networks, which removes the path by which attacker-controlled serialized objects reach the deserialization filter.

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

Upgrade ch.qos.logback:logback-core to version 1.5.33 or higher.

References

• Apache Jira Issues
• GitHub Commit
• Release Notes

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 in the isSafeSubType() method of DefaultBaseTypeLimitingValidator, whose denylist of unsafe base types omits java.lang.Comparable, so the method returns true for any subtype resolved under a Comparable base. An attacker can trigger instantiation of arbitrary classes that implement Comparable, such as java.io.File to reach path-traversal primitives, by sending JSON with attacker-controlled type identifiers. This requires the application to use a bare @JsonTypeInfo with the default validator and no explicit PolymorphicTypeValidator, and a property or class whose declared base type is Comparable.

Workaround

This vulnerability can be avoided by configuring an explicit restrictive PolymorphicTypeValidator, such as a BasicPolymorphicTypeValidator allowlist passed to activateDefaultTyping(), instead of relying on the default validator.

Note: The discoverer of this vulnerability reports that "I have not identified a class implementing Comparable that yields code execution purely through deserialization".

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

Upgrade com.fasterxml.jackson.core:jackson-databind to version 2.18.10, 2.21.6, 2.22.2 or higher.

References

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

Overview

org.lz4:lz4-java is a Java port of the LZ4 compression algorithm and the xxHash hashing algorithm.

Affected versions of this package are vulnerable to Uncontrolled Recursion in the refill function when processing LZ4 block streams with stopOnEmptyBlock set to false. An attacker can cause a thread to terminate unexpectedly by providing a stream with a large number of consecutive empty blocks, leading to stack exhaustion and application unavailability. This is only exploitable if the configuration option stopOnEmptyBlock is explicitly set to false.

Remediation

There is no fixed version for org.lz4:lz4-java.

References

• GitHub Advisory
• GitHub Commit
• GitHub Release

Overview

Affected versions of this package are vulnerable to Double Free via SnappyFramedInputStream in src/main/java/org/xerial/snappy/SnappyFramedInputStream.java. An attacker can make two SnappyFramedInputStream instances share the same backing array by supplying framed data with a large declared chunk length that triggers an allocation failure during buffer growth. When the stream returns its current direct and array buffers to the pool and the replacement allocation fails, close() can release the same buffers again. In deployments using the default caching buffer pool, a later stream may receive that reused buffer and read or overwrite another stream’s decompressed data.

Workarounds

• Discard the buffer pool after an OutOfMemoryError during decompression, so the same released buffers are not reused by later SnappyFramedInputStream instances.
• Pass a non-caching BufferPool to SnappyFramedInputStream, so buffers are not retained and handed out again to another stream after a failed allocation.

Remediation

Upgrade org.xerial.snappy:snappy-java to version 1.1.10.10 or higher.

References

• GitHub Commit
• Maintainer's Advisory

Overview

ch.qos.logback:logback-classic is a reliable, generic, fast and flexible logging library for Java.

Affected versions of this package are vulnerable to Directory Traversal in MDCBasedDiscriminator, used by SiftingAppender, which takes an MDC value as the discriminating key without removing path separators, so the value reaches the nested FileAppender path unsanitized. An attacker can direct log output to a file outside the intended directory by supplying an MDC value containing / or \ path segments. This requires a configuration whose SiftingAppender discriminates on MDC and whose nested FileAppender interpolates the discriminating key into its file path, with that MDC value populated from attacker-influenced input.

Note: This is a bypass of the fix for the vulnerability described in CVE-2025-11226.

Details

A Directory Traversal attack (also known as path traversal) aims to access files and directories that are stored outside the intended folder. By manipulating files with "dot-dot-slash (../)" sequences and its variations, or by using absolute file paths, it may be possible to access arbitrary files and directories stored on file system, including application source code, configuration, and other critical system files.

Directory Traversal vulnerabilities can be generally divided into two types:

• Information Disclosure: Allows the attacker to gain information about the folder structure or read the contents of sensitive files on the system.

st is a module for serving static files on web pages, and contains a vulnerability of this type. In our example, we will serve files from the public route.

If an attacker requests the following URL from our server, it will in turn leak the sensitive private key of the root user.

curl http://localhost:8080/public/%2e%2e/%2e%2e/%2e%2e/%2e%2e/%2e%2e/root/.ssh/id_rsa

Note %2e is the URL encoded version of . (dot).

• Writing arbitrary files: Allows the attacker to create or replace existing files. This type of vulnerability is also known as Zip-Slip.

One way to achieve this is by using a malicious zip archive that holds path traversal filenames. When each filename in the zip archive gets concatenated to the target extraction folder, without validation, the final path ends up outside of the target folder. If an executable or a configuration file is overwritten with a file containing malicious code, the problem can turn into an arbitrary code execution issue quite easily.

The following is an example of a zip archive with one benign file and one malicious file. Extracting the malicious file will result in traversing out of the target folder, ending up in /root/.ssh/ overwriting the authorized_keys file:

2018-04-15 22:04:29 .....           19           19  good.txt
2018-04-15 22:04:42 .....           20           20  ../../../../../../root/.ssh/authorized_keys

Remediation

Upgrade ch.qos.logback:logback-classic to version 1.6.3 or higher.

References

• GitHub Commit
• Release Notes

Overview

Affected versions of this package are vulnerable to Out-of-bounds Read via the getFrameContentSize(byte[], int, int, boolean) bounds check in src/main/java/com/github/luben/zstd/Zstd.java. An attacker can trigger a JVM crash or read past the start of the input buffer by supplying a negative srcPosition when calling this public API. The method only rejected offsets at or beyond src.length, so a negative offset and matching length could reach the native frame-header parser with an invalid pointer into attacker-controlled input.

Remediation

Upgrade com.github.luben:zstd-jni to version 1.5.7-14 or higher.

References

• GitHub Commit
• Maintainer's Advisory
• Vulnerable Code
• Vulnerable 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 Incorrect Authorization in the BeanDeserializer._deserializeUsingPropertyBased method, whose property-buffering branch omits the prop.visibleInView(activeView) check that the creator-property branch performs. An attacker can populate view-restricted setterless collection or map properties, such as admin-only fields, from untrusted JSON by supplying values for them during deserialization, bypassing @JsonView protection. This affects only setterless collection or map properties annotated with a restricted @JsonView and reached through the property-based creator path.

Remediation

Upgrade com.fasterxml.jackson.core:jackson-databind to version 2.21.4 or higher.

References

• GitHub Advisory
• GitHub Commit
• GitHub Commit
• GitHub PR
• 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 Incorrect Authorization in the UnwrappedPropertyHandler.processUnwrappedCreatorProperties() method, which replays buffered JSON into creator parameters without consulting prop.visibleInView(activeView). An attacker can set view-restricted constructor parameters annotated with both @JsonView and @JsonUnwrapped, such as admin-only fields, from untrusted JSON by supplying them during deserialization while a more restrictive view is active, defeating the @JsonView write-side authorization boundary.

Remediation

Upgrade com.fasterxml.jackson.core:jackson-databind to version 2.21.4 or higher.

References

• GitHub Advisory
• GitHub Commit
• GitHub Commit
• GitHub PR
• 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 Incorrect Authorization in the deserializeUsingPropertyBasedWithExternalTypeId file. An attacker can populate restricted creator properties from untrusted input by crafting JSON that exploits the lack of view checks on parameters annotated with both @JsonView and @JsonTypeInfo(include=As.EXTERNAL_PROPERTY). This allows unauthorized assignment of sensitive fields, even when a restrictive view is active, by injecting values through polymorphic type information.

Remediation

Upgrade com.fasterxml.jackson.core:jackson-databind to version 2.18.9, 2.21.5 or higher.

References

• GitHub Advisory
• GitHub Commit
• GitHub Commit

Overview

Affected versions of this package are vulnerable to Infinite loop due to negative length validation in read(byte[], int, int) in src/main/java/com/github/luben/zstd/ZstdInputStreamNoFinalizer.java. An attacker can spin a caller thread indefinitely by supplying a negative len to read(), which leaves the method retrying without making progress. Because the method is synchronized, the stuck read holds the stream’s monitor and blocks other threads that try to use the same ZstdInputStreamNoFinalizer instance, causing a thread-exhaustion denial of service.

Remediation

Upgrade com.github.luben:zstd-jni to version 1.5.7-14 or higher.

References

• GitHub Commit
• Maintainer's Advisory
• Vulnerable Code