Integer Overflow Vulnerability in libXfixes: Remote Privilege Escalation Risk
Summary
DEBIAN-CVE-2016-7944: Integer overflow in X.org libXfixes before 5.0.3 on 32-bit platforms might allow remote X servers to gain privileges via a length value of INT_MAX, which triggers the client to stop reading data and get out of sync. Affects libxfixes versions < 1:5.0.3-1. Fixed in 1:5.0.3-1. How to fix ↓
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Background
libXfixes is a library used in the X Window System that provides support for various X server extensions. It is essential for managing graphical operations and enhancing the performance of X applications. This library is widely utilized in various Linux distributions, including Debian. The vulnerability in question affects versions of libXfixes prior to 5.0.3, specifically on 32-bit platforms, making it susceptible to exploitation by remote X servers.
Vulnerability Detail
The vulnerability arises from an integer overflow in libXfixes before version 5.0.3. When a length value of INT_MAX is processed, it can cause the client to stop reading data, leading to a desynchronization between the client and server. This desynchronization can be exploited by remote attackers to gain elevated privileges, posing a significant security risk to systems utilizing this library.
How To Fix
Minimum fixed version
1:5.0.3-1
This is the first release that contains the fix.
sudo apt-get install --only-upgrade libxfixesTip — Not sure which version your app runs? Vulert can match this fix to it. Scan free →
Workaround
As a temporary workaround, users can restrict access to the X server or implement firewall rules to limit connections from untrusted sources. This can help mitigate the risk of exploitation until the library is updated.
Conclusion
The integer overflow vulnerability in libXfixes poses a significant risk to systems running versions prior to 5.0.3, particularly on 32-bit platforms. It is essential to update to the patched version to mitigate this risk. Users are also encouraged to explore Vulert for real-time monitoring of open-source vulnerabilities.
See every vulnerability recorded for libxfixes →
FAQ
libXfixes is a library that provides support for X server extensions, enhancing the graphical performance of applications in the X Window System.
The vulnerability involves an integer overflow that can allow remote X servers to gain elevated privileges on affected systems.
You can check if your application is affected by using the Vulert playground at Vulert Scanner, which allows you to monitor for open-source vulnerabilities without requiring installation.
If immediate updates are not possible, consider implementing firewall rules to limit access to the X server as a temporary measure.
While the primary risk is privilege escalation, exploitation could potentially lead to unauthorized access to sensitive data, depending on the attacker's actions.
References
Related vulnerabilities
Recent vulnerabilities recorded for libxfixes.
