CVE-2025-20748

// CVE-2025-20748 PoC - MediaTek WLAN AP Driver OOB Write // This is a conceptual PoC demonstrating the vulnerability pattern // Note: Actual exploitation requires specific MediaTek firmware and environment #include <stdio.h> #include <stdlib.h> #include <string.h> // Simulated vulnerable function structure struct wlan_packet { unsigned char header[16]; unsigned char data[256]; unsigned int length; }; // Vulnerable function with incorrect bounds check void process_wlan_packet_vulnerable(struct wlan_packet *pkt) { // VULNERABLE: Incorrect bounds check // Should check: pkt->length <= sizeof(pkt->data) if (pkt->length < 1024) { // Wrong condition! // This allows writing beyond buffer boundary memcpy(pkt->data, pkt->header, pkt->length); } } // Corrected function with proper bounds check void process_wlan_packet_safe(struct wlan_packet *pkt) { // FIXED: Proper bounds check if (pkt->length <= sizeof(pkt->data)) { memcpy(pkt->data, pkt->header, pkt->length); } } int main() { printf("CVE-2025-20748 - MediaTek WLAN AP Driver OOB Write\n"); printf("Vulnerability: Incorrect bounds check in wlan AP driver\n"); printf("Impact: Local privilege escalation\n"); struct wlan_packet pkt; memset(&pkt, 0, sizeof(pkt)); // Simulate malicious packet with length > buffer size pkt.length = 512; // Exceeds data buffer size of 256 memset(pkt.header, 0x41, 16); printf("\nTesting vulnerable function...\n"); process_wlan_packet_vulnerable(&pkt); printf("Testing safe function...\n"); process_wlan_packet_safe(&pkt); return 0; } // Mitigation: // 1. Apply MediaTek security patch WCNCR00432679 // 2. Update WLAN driver to latest version // 3. Implement proper input validation and bounds checking

{"cve": {"id": "CVE-2025-20748", "sourceIdentifier": "[email protected]", "published": "2025-11-04T07:15:50.343", "lastModified": "2026-01-13T06:15:49.650", "vulnStatus": "Modified", "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 local escalation of privilege if a malicious actor has already obtained the System privilege. User interaction is not needed for exploitation. Patch ID: WCNCR00432679; Issue ID: MSV-3950."}], "metrics": {"cvssMetricV31": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "type": "Secondary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H", "baseScore": 6.7, "baseSeverity": "MEDIUM", "attackVector": "LOCAL", "attackComplexity": "LOW", "privilegesRequired": "HIGH", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "availabilityImpact": "HIGH"}, "exploitabilityScore": 0.8, "impactScore": 5.9}]}, "weaknesses": [{"source": "[email protected]", "type": "Primary", "description": [{"lang": "en", "value": "CWE-787"}]}, {"source": "[email protected]", "type": "Secondary", "description": [{"lang": "en", "value": "CWE-787"}]}], "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"}, {"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"}, {"vulnerable": false, "criteria": "cpe:2.3:h:mediatek:mt7615:-:*:*:*:*:*:*:*", "matchCriteriaId": "05748BB1-0D48-4097-932E-E8E2E574FD8D"}, {"vulnerable": false, "criteria": "cpe:2.3:h:mediatek:mt7622:-:*:*:*:*:*:*:*", "matchCriteriaId": "55EB4B27-6264-45BE-9A22-BE8418BB0C06"}, {"vulnerable": false, "criteria": "cpe:2.3:h:mediatek:mt7663:-:*:*:*:*:*:*:*", "matchCriteriaId": "10C79211-F064-499D-914E-0BACD038FBF4"}, {"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"}]}]}], "references": [{"url": "https://corp.mediatek.com/product-security-bulletin/November-2025", "source": "[email protected]", "tags": ["Vendor Advisory"]}]}}