CVE-2021-30159 : Exploit Details and Defense Strategies

An issue was discovered in MediaWiki before 1.31.12 and 1.32.x through 1.35.x before 1.35.2. Users can bypass intended restrictions on deleting pages in certain "fast double move" situations.

Understanding CVE-2021-30159

This CVE identifies a vulnerability in MediaWiki versions prior to 1.31.12 and 1.32.x through 1.35.x before 1.35.2 that allows users to circumvent page deletion restrictions in specific scenarios.

What is CVE-2021-30159?

The issue in MediaWiki enables users to delete pages by exploiting certain conditions, potentially leading to unauthorized deletion of content.

The Impact of CVE-2021-30159

This vulnerability can be exploited by attackers to bypass deletion restrictions within MediaWiki, compromising the integrity and availability of content on affected platforms.

Technical Details of CVE-2021-30159

CVE-2021-30159 involves a flaw in MovePage::isValidMoveTarget() and MovePage::moveToInternal() functions within MediaWiki, allowing users to delete pages under specific circumstances.

Vulnerability Description

MovePage::isValidMoveTarget() and MovePage::moveToInternal() functions are manipulated to delete pages when certain conditions are met, enabling unauthorized deletions.

Affected Systems and Versions

MediaWiki versions before 1.31.12 and 1.35.2 are vulnerable to this issue, impacting systems running these specific versions.

Exploitation Mechanism

Attackers can exploit this vulnerability by creating conditions that trigger the deletion of pages, leveraging the flawed functions in MediaWiki to bypass intended restrictions.

Mitigation and Prevention

To address CVE-2021-30159, immediate steps should be taken to secure affected systems and prevent potential exploitation.

Immediate Steps to Take

Users are advised to update their MediaWiki installations to versions 1.31.12, 1.35.2, or newer to mitigate the risks associated with this vulnerability.

Long-Term Security Practices

Regularly monitoring security advisories and promptly applying patches can help safeguard systems against known vulnerabilities like CVE-2021-30159.

Patching and Updates

Keep MediaWiki up to date with the latest security patches and updates to prevent exploitation of identified vulnerabilities.