Critical Use-After-Free Vulnerability in libxml2 Affects Multiple Alpine Versions
Summary
ALPINE-CVE-2021-3518: There's a flaw in libxml2 in versions before 2.9.11. Affects libxml2 versions < 2.9.9-r5. Fixed in 2.9.9-r5. How to fix ↓
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Background
libxml2 is a widely-used XML parsing library that provides a range of functionalities for processing XML and HTML documents. It is known for its performance and compliance with standards. However, versions prior to 2.9.11 are vulnerable to a critical use-after-free flaw, which can lead to severe security implications.
Vulnerability Detail
There's a flaw in libxml2 in versions before 2.9.11. An attacker who is able to submit a crafted file to be processed by an application linked with libxml2 could trigger a use-after-free. This vulnerability can compromise confidentiality, integrity, and availability, allowing attackers to exploit the flaw for malicious purposes.
How To Fix
Minimum fixed version
2.9.9-r5
This is the first release that contains the fix.
sudo apk add --upgrade libxml2Tip — Not sure which version your app runs? Vulert can match this fix to it. Scan free →
Workaround
If an immediate update is not possible, consider implementing input validation to sanitize any XML files before processing them with libxml2. This can help mitigate the risk of exploitation.
Conclusion
The use-after-free vulnerability in libxml2 poses significant risks to applications that rely on this library. It is crucial to update to the patched versions to safeguard against potential exploits. Regular monitoring and validation of dependencies can help maintain security.
See every vulnerability recorded for libxml2 →
FAQ
The CVSS score of this vulnerability is 8.8, indicating a high severity level.
All versions of libxml2 prior to 2.9.11 are affected by this vulnerability.
You can use Vulert, which monitors and alerts for open-source vulnerabilities in your software. You can check your application using the Vulert playground without any signup.
The vulnerability can lead to unauthorized access, data corruption, and denial of service, affecting the confidentiality, integrity, and availability of the system.
Yes, implementing input validation to sanitize XML files before processing can help mitigate the risk until an update is applied.
References
Related vulnerabilities
Recent vulnerabilities recorded for libxml2.
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