CVE-2021-41800 : What You Need to Know
Learn about CVE-2021-41800, a MediaWiki vulnerability allowing denial of service attacks due to lengthy query processing. Find mitigation steps and affected versions.
MediaWiki before 1.36.2 allows a denial of service due to lengthy query processing time.
Understanding CVE-2021-41800
What is CVE-2021-41800?
MediaWiki before version 1.36.2 is vulnerable to a denial of service attack caused by resource consumption due to extended query processing time when visiting Special:Contributions due to mishandling PoolCounter protection.
The Impact of CVE-2021-41800
This vulnerability can lead to a denial of service by exhausting server resources, potentially disrupting services for legitimate users.
Technical Details of CVE-2021-41800
Vulnerability Description
The issue arises from lengthy query processing, particularly when navigating to Special:Contributions in MediaWiki versions earlier than 1.36.2.
Affected Systems and Versions
- Vendor: n/a
- Product: n/a
- Affected Version: All versions before 1.36.2
Exploitation Mechanism
Attackers can exploit this vulnerability by triggering Special:Contributions, causing a lengthy SQL query that overwhelms the server, leading to a denial of service.
Mitigation and Prevention
Immediate Steps to Take
- Upgrade MediaWiki to version 1.36.2, which contains a fix for this denial of service vulnerability.
- Monitor server resources for any signs of unusual consumption.
Long-Term Security Practices
- Regularly update software to the latest stable versions to patch known vulnerabilities.
- Implement rate limiting and query optimizations to prevent resource exhaustion attacks.
- Conduct security audits and penetration testing to identify and address potential weaknesses.
Patching and Updates
Ensure timely installation of security patches and updates provided by MediaWiki to mitigate the risk of denial of service attacks.