Remote Code Execution Vulnerability in libxstream-java: CVE-2021-39141
Summary
CVE-2021-39141: XStream is a simple library to serialize objects to XML and back again. Affects libxstream-java across 2 version ranges.
< 1.4.15-3+deb11u1
< b9ad1c02724c2b1636a8794c8e1bcd630f46c0b3
Fixed in 1.4.15-3+deb11u1. How to fix ↓
Check if this vulnerability affects your application
Upload a manifest or SBOM and we'll show whether you're affected, plus every other risky package in the same scan.
No signup required · Results in about 60 seconds
Background
libxstream-java is a library that facilitates the serialization of Java objects to XML and vice versa. It is widely used in various Java applications for data interchange. The library's functionality allows developers to easily convert complex data structures into a format that can be easily transmitted or stored. However, its flexibility also makes it susceptible to security vulnerabilities, particularly when input streams are not properly validated.
Vulnerability Detail
CVE-2021-39141 is a critical vulnerability in libxstream-java that allows remote attackers to execute arbitrary code by manipulating the input stream processed by the library. This vulnerability arises from the library's previous reliance on a blacklist approach for security, which has proven ineffective for general-purpose use. If the security framework is not configured correctly, an attacker can exploit this flaw to load and execute malicious code from a remote host, posing significant risks to affected systems.
How To Fix
Minimum fixed version
1.4.15-3+deb11u1
This is the first release that contains the fix.
sudo apt-get install --only-upgrade libxstream-javaTip — Not sure which version your app runs? Vulert can match this fix to it. Scan free →
Workaround
As a temporary workaround, if upgrading is not immediately possible, you can implement a security framework configuration that restricts the types of objects that can be deserialized. This can be done by setting up a whitelist of allowed classes in your application code, ensuring that only safe types are processed. Example code snippet:
XStream xstream = new XStream();
// Allow only specific classes
xstream.allowTypes(new Class[]{AllowedClass1.class, AllowedClass2.class});
Conclusion
CVE-2021-39141 is a significant vulnerability in libxstream-java that poses serious risks if not addressed. By upgrading to the latest versions and implementing proper security configurations, users can protect their applications from potential exploits. Regular monitoring for vulnerabilities using tools like Vulert can further enhance security.
See every vulnerability recorded for libxstream-java →
FAQ
CVE-2021-39141 is a vulnerability in libxstream-java that allows remote code execution through manipulated input streams.
You can check if your application is affected by using the Vulert playground at Vulert Scanner, which analyzes your manifest file for vulnerabilities.
Exploitation of this vulnerability can lead to unauthorized remote code execution, potentially compromising the entire system.
Affected versions include those prior to 1.4.15-3+deb11u1 for Debian 11 and prior to 1.4.18-1 for Debian 12 and 13.
The CVSS score of CVE-2021-39141 is 8.5, indicating a high severity level.
Related vulnerabilities
Recent vulnerabilities recorded for libxstream-java.
