CVE-2021-41799 : Exploit Details and Defense Strategies
Learn about CVE-2021-41799 affecting MediaWiki before 1.36.2, allowing denial of service attacks through resource exhaustion. Find out how to mitigate and prevent this vulnerability.
MediaWiki before version 1.36.2 is susceptible to a denial of service attack due to lengthy query processing time. The specific vulnerability lies in ApiQueryBacklinks (action=query&list=backlinks) and can lead to resource exhaustion through a full table scan.
Understanding CVE-2021-41799
This CVE affects MediaWiki instances prior to version 1.36.2, potentially allowing attackers to exploit the service and cause resource consumption.
What is CVE-2021-41799?
CVE-2021-41799 relates to a vulnerability in MediaWiki versions before 1.36.2 that can be abused to carry out a denial of service attack by causing excessive resource usage during query processing.
The Impact of CVE-2021-41799
The exploitation of this vulnerability could result in a denial of service condition for affected MediaWiki instances, leading to resource exhaustion and potential service unavailability.
Technical Details of CVE-2021-41799
MediaWiki before version 1.36.2 is vulnerable due to a specific issue with the ApiQueryBacklinks functionality. Here are the technical details related to this CVE:
Vulnerability Description
The vulnerability allows for a denial of service attack by triggering a full table scan, leading to extensive resource consumption during query processing.
Affected Systems and Versions
- Affected Systems: MediaWiki instances running versions below 1.36.2
- Affected Versions: All versions before 1.36.2
Exploitation Mechanism
Attackers can exploit this vulnerability by sending crafted requests to the ApiQueryBacklinks functionality, causing the system to perform a full table scan and resulting in resource exhaustion.
Mitigation and Prevention
To address CVE-2021-41799 and mitigate the associated risks, consider the following steps:
Immediate Steps to Take
- Upgrade affected MediaWiki instances to version 1.36.2 or newer to prevent exploitation.
- Monitor resource usage to detect any unusual spikes indicating a potential denial of service attack.
Long-Term Security Practices
- Implement rate limiting to cap the number of requests that can be processed, reducing the impact of potential attacks.
- Regularly review and update configuration settings to ensure optimal security measures.
Patching and Updates
Apply security patches provided by MediaWiki promptly to address known vulnerabilities and protect the system from exploitation.