Heap-buffer-overflow in xmlParseCommentComplex in libxml2
Summary
OSV-2023-999: Heap-buffer-overflow in xmlParseCommentComplex. Affects libxml2 versions >= 8afd321abd2f75cf795f679b54333237b364d4d9, < 4fc5340ec55a12cd6819395030d5d132a219984a. Fixed in 4fc5340ec55a12cd6819395030d5d132a219984a. How to fix ↓
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Background
libxml2 is an open-source library for parsing and manipulating XML files. It provides a set of functions and APIs to handle XML data. The library is widely used in various applications and frameworks. However, a vulnerability has been discovered in the xmlParseCommentComplex function of libxml2, which can lead to a heap-buffer-overflow write. This vulnerability can be exploited by an attacker to execute arbitrary code or cause a denial-of-service condition.
Vulnerability Detail
The vulnerability originates from a heap-buffer-overflow write in the xmlParseCommentComplex function of libxml2. When parsing a specially crafted XML comment, the function fails to properly validate the input, leading to a buffer overflow. This can result in overwriting adjacent memory regions, potentially allowing an attacker to execute arbitrary code or crash the application. The vulnerability has been assigned a high severity rating.
How To Fix
Minimum fixed version
4fc5340ec55a12cd6819395030d5d132a219984a
This is the first release that contains the fix.
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Workaround
As a temporary workaround, developers can implement input validation and sanitization measures when processing XML comments. This can help mitigate the risk of exploitation. Here is an example of how to sanitize XML comments using a regular expression in Python:
import re
def sanitize_xml_comment(comment):
sanitized_comment = re.sub(r'--', '', comment)
return sanitized_comment
This code snippet removes any double hyphens from the XML comment, which can help prevent the vulnerability from being triggered.
Conclusion
The heap-buffer-overflow vulnerability in xmlParseCommentComplex in libxml2 can have severe consequences, including arbitrary code execution and denial-of-service. It is crucial to update the libxml2 library to a patched version that addresses this vulnerability. Additionally, implementing input validation and sanitization measures can provide temporary protection. For further assistance and support in vulnerability remediation, please contact DevNack.com.
See every vulnerability recorded for libxml2 →
FAQ
libxml2 is an open-source library for parsing and manipulating XML files. It provides a set of functions and APIs to handle XML data.
The vulnerability can be exploited by an attacker to execute arbitrary code or cause a denial-of-service condition.
To fix this vulnerability, update the libxml2 library to a version that includes the fix.
As a temporary workaround, implement input validation and sanitization measures when processing XML comments.
For more information about this vulnerability, refer to the OSS-Fuzz report linked in the details section.
References
Related vulnerabilities
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