CVE-2021-31548 : Security Advisory and Response

An issue was discovered in the AbuseFilter extension for MediaWiki through 1.35.2. This vulnerability allowed a MediaWiki user who is partially blocked or unsuccessfully blocked to bypass AbuseFilter and complete their edits.

Understanding CVE-2021-31548

This section will discuss the impact, technical details, and mitigation strategies related to CVE-2021-31548.

What is CVE-2021-31548?

CVE-2021-31548 is a security vulnerability found in the AbuseFilter extension for MediaWiki through version 1.35.2. It enables partially blocked or unsuccessful blocked users to bypass the AbuseFilter mechanism.

The Impact of CVE-2021-31548

The vulnerability in CVE-2021-31548 could potentially allow malicious users to circumvent the AbuseFilter protection and make edits that would otherwise be restricted. This could lead to unauthorized content modification and abuse of the MediaWiki platform.

Technical Details of CVE-2021-31548

In this section, we will delve into the specifics of the vulnerability, the affected systems and versions, as well as the exploitation mechanism.

Vulnerability Description

The security flaw in the AbuseFilter extension for MediaWiki allowed users with partial or failed blocks to bypass the filter and successfully complete their edits, undermining the intended restrictions.

Affected Systems and Versions

Systems running MediaWiki versions up to 1.35.2 with the AbuseFilter extension are vulnerable to CVE-2021-31548.

Exploitation Mechanism

By exploiting this vulnerability, unauthorized users could evade the AbuseFilter protection mechanism and proceed with making edits on MediaWiki, even if they were partially or unsuccessfully blocked.

Mitigation and Prevention

This section covers the immediate steps to take, best security practices, and the importance of patching and updates.

Immediate Steps to Take

To mitigate the risk posed by CVE-2021-31548, users are advised to update their MediaWiki installations to a secure version that includes a patch for this vulnerability.

Long-Term Security Practices

In the long term, organizations should enforce proper user access controls, regularly monitor user activities, and educate users on security best practices to prevent similar incidents.

Patching and Updates

Regularly applying security patches and updates provided by MediaWiki is crucial to ensure that known vulnerabilities like CVE-2021-31548 are addressed promptly.