Critical Remote Code Execution Vulnerability in libxstream-java
Summary
DEBIAN-CVE-2021-39146: XStream is a simple library to serialize objects to XML and back again. Affects libxstream-java versions < 1.4.15-3+deb11u1. 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 widely used library that facilitates the serialization of Java objects to XML and vice versa. It is known for its simplicity and flexibility, allowing developers to easily convert Java objects into XML format for storage or transmission. However, certain versions of this library have been found to be vulnerable to a critical security flaw that could allow remote attackers to execute arbitrary code.
Vulnerability Detail
The vulnerability in libxstream-java arises from its handling of input streams. Specifically, affected versions allow a remote attacker to manipulate the processed input stream, potentially leading to the execution of arbitrary code from a remote host. This issue is particularly concerning as it can be exploited without any user interaction, posing a significant risk to systems utilizing the library. The vulnerability is rooted in the library's previous reliance on a blacklist security model, which has been deemed insecure for general-purpose use. The introduction of a whitelist model in version 1.4.18 mitigates this risk, but earlier versions remain susceptible.
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 measure, users are advised to implement XStream's security framework by setting up a whitelist that limits the types of objects that can be deserialized. This can help mitigate the risk until the package is updated to a secure version.
Conclusion
The libxstream-java library has a critical vulnerability that can lead to remote code execution if not addressed. Users are strongly encouraged to update to the latest patched versions and implement security best practices to safeguard their applications. Utilizing tools like Vulert can help monitor and alert for such vulnerabilities in real-time.
See every vulnerability recorded for libxstream-java →
FAQ
libxstream-java is a library that allows for the serialization of Java objects to XML and back, making it easier to store and transmit Java objects.
The vulnerability allows remote attackers to execute arbitrary code by manipulating the input stream processed by the library.
You can use Vulert's playground at Vulert Scanner to check if your application is affected by this vulnerability without needing to sign up.
Versions prior to 1.4.15-3+deb11u1 for Debian 11 and 1.4.18-1 for Debian 12, 13, and 14 are affected by this vulnerability.
Implement a whitelist in XStream's security framework to limit deserialization to only the necessary types as a temporary workaround.
References
Related vulnerabilities
Recent vulnerabilities recorded for libxstream-java.
