Semantic MediaWiki 3.0.0 before 7.3.1 Denial of Service via Special:Search Compact Filters

Summary

Semantic MediaWiki from 3.0.0 before 7.3.1 contains an algorithmic complexity vulnerability in TermParser::normalize_compact_form() that allows unauthenticated attackers to cause quadratic CPU consumption. Attackers can submit long search terms with many distinct in:(...) or has:(...) expressions to Special:Search to exhaust PHP search workers when the extended search engine is enabled.

Remediation

1. Inventory every SemanticMediaWiki SemanticMediaWiki deployment, including staging.
2. Upgrade SemanticMediaWiki SemanticMediaWiki to 7.3.1.
3. Confirm the running version after the upgrade.

References

• Patchhttps://github.com/SemanticMediaWiki/SemanticMediaWiki/commit/c2bf1699dec4016e21ce52613152bda799ce87d4
• Advisoryhttps://github.com/SemanticMediaWiki/SemanticMediaWiki/security/advisories/GHSA-j2r2-7qpg-p675
• Advisoryhttps://www.vulncheck.com/advisories/semantic-mediawiki-3.0.0-before-7.3.1-denial-of-service-via-special-search-compact-filters