Denial of Service Vulnerability in libexpat
Summary
CVE-2023-52425: libexpat through 2.5.0 allows a denial of service (resource consumption) because many full reparsings are required in the case of a large token for which multiple buffer fills are needed. Affects expat across 2 version ranges.
< 2.6.0-r0
< 654d2de0da85662fcc7644a7acd7c2dd2cfb21f0
Fixed in 2.6.0-r0. How to fix ↓
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Background
libexpat is a widely used open-source library for parsing XML documents. It provides a set of functions and APIs that allow developers to parse and process XML data efficiently. However, versions up to 2.5.0 of libexpat are vulnerable to a denial of service attack. This vulnerability can be exploited by an attacker to consume excessive system resources, leading to a degradation in performance or even a complete system crash.
Vulnerability Detail
The vulnerability in libexpat arises from the need for multiple full reparsings when processing a large token that requires multiple buffer fills. This can be exploited by an attacker to craft malicious XML data that triggers the repetitive reparsing process, causing a significant increase in resource consumption. As a result, the targeted system may become unresponsive or crash due to resource exhaustion.
How To Fix
Minimum fixed version
2.6.0-r0
This is the first release that contains the fix.
sudo apk add --upgrade expatTip — Not sure which version your app runs? Vulert can match this fix to it. Scan free →
Workaround
If updating libexpat is not immediately feasible, a temporary workaround is to limit the size of the XML input or implement input validation to reject excessively large tokens. However, this workaround may impact the functionality or compatibility of the affected application, and it is strongly advised to update to the latest version of libexpat as soon as possible.
Conclusion
The denial of service vulnerability in libexpat can be mitigated by updating to version 2.6.0-r0 or later. It is important to promptly apply the necessary patches to ensure the security and stability of applications that rely on libexpat. For further assistance or support in vulnerability remediation, please contact DevNack.com.
See every vulnerability recorded for expat →
FAQ
libexpat is an open-source library for parsing XML documents. It provides functions and APIs for efficient XML data processing.
The vulnerability allows an attacker to consume excessive system resources, leading to a denial of service condition. This can result in system slowdowns, unresponsiveness, or even crashes.
To fix this vulnerability, update libexpat to version 2.6.0-r0 or later. Rebuild your applications using the updated version.
A temporary workaround is to limit the size of XML input or implement input validation to reject excessively large tokens. However, updating to the latest version is strongly recommended.
For more information about this vulnerability, refer to the official CVE-2023-52425 entry or visit the Vulert playground at Vulert Scanner.
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