Semantic MediaWiki 3.0.0 before 7.3.1 Uncontrolled Recursion via Special:Ask

Summary

Semantic MediaWiki 3.0.0 before 7.3.1 contains an uncontrolled recursion vulnerability in LegacyParser::getSubqueryDescription() that processes nested query tokens before depth limits apply. Unauthenticated attackers can submit deeply nested query elements to the action=ask API to consume substantial CPU and memory, tying up request workers.

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/756492002752f937a9e115e14330b1181bd8c60c
• Patchhttps://github.com/SemanticMediaWiki/SemanticMediaWiki/commit/e642f38c708dee7da5e885b8d40be8ffc56f3e87
• Advisoryhttps://github.com/SemanticMediaWiki/SemanticMediaWiki/security/advisories/GHSA-f8vw-wvm6-h2qq
• Advisoryhttps://www.vulncheck.com/advisories/semantic-mediawiki-3.0.0-before-7.3.1-uncontrolled-recursion-via-special-ask