CVE-2021-31547 : Vulnerability Insights and Analysis

An issue was discovered in the AbuseFilter extension for MediaWiki through version 1.35.2, where its AbuseFilterCheckMatch API exposes suppressed edits and usernames to unauthorized users through manipulated AbuseFilter rules.

Understanding CVE-2021-31547

This CVE identifies a security flaw in the AbuseFilter extension of MediaWiki that allows unprivileged users to gain access to suppressed edits and usernames by exploiting crafted AbuseFilter rules.

What is CVE-2021-31547?

The CVE-2021-31547 highlights a vulnerability in MediaWiki's AbuseFilter extension up to version 1.35.2. The flaw enables unauthorized users to view suppressed edits and usernames by misusing the AbuseFilterCheckMatch API.

The Impact of CVE-2021-31547

The impact of this vulnerability could lead to unauthorized disclosure of sensitive information such as suppressed edits and usernames, compromising user privacy and security within the MediaWiki platform.

Technical Details of CVE-2021-31547

This section provides detailed technical insights into the CVE-2021-31547 vulnerability.

Vulnerability Description

The issue arises from the AbuseFilterCheckMatch API within the AbuseFilter extension for MediaWiki, which inadvertently exposes suppressed edits and usernames to unprivileged users through the manipulation of AbuseFilter rules.

Affected Systems and Versions

The vulnerability affects MediaWiki installations utilizing the AbuseFilter extension up to version 1.35.2. Users of these versions are at risk of unauthorized access to suppressed edits and usernames.

Exploitation Mechanism

By crafting malicious AbuseFilter rules, unauthorized users can exploit the AbuseFilterCheckMatch API to retrieve suppressed edits and usernames, bypassing intended access restrictions.

Mitigation and Prevention

To mitigate the risks associated with CVE-2021-31547, immediate actions and long-term security measures should be implemented.

Immediate Steps to Take

MediaWiki administrators should restrict access to the AbuseFilterCheckMatch API and apply the necessary patches to address the vulnerability promptly.

Long-Term Security Practices

Regular security audits and user access reviews should be conducted to prevent unauthorized access to sensitive information within the MediaWiki platform.

Patching and Updates

Users are advised to update their MediaWiki installations to version 1.35.3 or later, where the vulnerability has been addressed and patched.