GHSA-wh64-r5x2-vjgf: Semantic MediaWiki 2.5.0 before 7.3.1 Resource Exhaustion via Special:PropertyLabelSimilarity
Semantic MediaWiki from 2.5.0 before 7.3.1 contains an uncontrolled resource consumption vulnerability that allows anonymous attackers to force quadratic computation by supplying a zero limit to Special:PropertyLabelSimilarity. Attackers can send repeated requests with limit=0 to bypass the SQL LIMIT and trigger pairwise similartext() comparisons, exhausting PHP CPU, memory, and database connections.
Event History
Frequently Asked Questions
Which deployments are exposed to unauthenticated exploitation?
Deployments running an affected Semantic MediaWiki version expose this issue to anonymous attackers through Special:PropertyLabelSimilarity. No authentication or user interaction is required.
What request pattern triggers the resource exhaustion?
An attacker supplies limit=0 to Special:PropertyLabelSimilarity and can repeat the request. A zero limit bypasses the SQL LIMIT, causing quadratic pairwise similar_text() comparisons that consume PHP CPU, memory, and database connections.
What is the impact of repeated exploitation?
Repeated requests can exhaust PHP CPU, memory, and database connections, resulting in resource exhaustion. The provided impact data indicates availability impact, with no stated confidentiality or integrity impact.
Which versions need remediation?
Semantic MediaWiki versions from 2.5.0 before 7.3.1 are affected. Upgrade to 7.3.1 or later.