CVE-2026-20446

#include <stdio.h> #include <stdint.h> // Conceptual PoC demonstrating Integer Overflow leading to Out-of-Bounds Write // This simulates the logic flaw in the sec boot component void trigger_vulnerability(uint32_t data_size) { // Simulate the integer overflow condition // If data_size is large (e.g., 0xFFFFFFFF), adding 1 wraps to 0 uint32_t alloc_size = data_size + 1; if (alloc_size < data_size) { printf("Integer overflow detected in allocation size calculation.\n"); // In the vulnerable scenario, this check might be missing or bypassed return; } // Allocation based on the overflowed size (potentially very small) char buffer[100]; // Fixed buffer for demonstration // The actual write loop uses the original large size, causing OOB write for (uint32_t i = 0; i < data_size; i++) { // This writes past the buffer boundary if data_size > 100 if (i < 100) { buffer[i] = 'A'; } else { // Memory corruption occurs here *((char*)(buffer + i)) = 'A'; } } } int main() { printf("Simulating CVE-2026-20446 PoC...\n"); // Input value intended to trigger the overflow logic trigger_vulnerability(0xFFFFFFFF); return 0; }

{"cve": {"id": "CVE-2026-20446", "sourceIdentifier": "[email protected]", "published": "2026-04-07T04:17:13.797", "lastModified": "2026-04-07T15:43:45.250", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "In sec boot, there is a possible out of bounds write due to an integer overflow. This could lead to local denial of service, if an attacker has physical access to the device, with User execution privileges needed. User interaction is not needed for exploitation. Patch ID: ALPS09963054; Issue ID: MSV-3899."}, {"lang": "es", "value": "En el arranque seguro, existe una posible escritura fuera de límites debido a un desbordamiento de entero. Esto podría llevar a una denegación de servicio local, si un atacante tiene acceso físico al dispositivo, con los privilegios de ejecución de usuario necesarios. No se necesita interacción del usuario para la explotación. ID del parche: ALPS09963054; ID del problema: MSV-3899."}], "metrics": {"cvssMetricV31": [{"source": "[email protected]", "type": "Primary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:P/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H", "baseScore": 4.3, "baseSeverity": "MEDIUM", "attackVector": "PHYSICAL", "attackComplexity": "LOW", "privilegesRequired": "LOW", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "availabilityImpact": "HIGH"}, "exploitabilityScore": 0.7, "impactScore": 3.6}, {"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "type": "Secondary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:P/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H", "baseScore": 4.3, "baseSeverity": "MEDIUM", "attackVector": "PHYSICAL", "attackComplexity": "LOW", "privilegesRequired": "LOW", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "availabilityImpact": "HIGH"}, "exploitabilityScore": 0.7, "impactScore": 3.6}]}, "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-190"}]}], "configurations": [{"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"}]}]}], "references": [{"url": "https://corp.mediatek.com/product-security-bulletin/April-2026", "source": "[email protected]", "tags": ["Vendor Advisory"]}]}}