CVE-2026-20810

// CVE-2026-20810 PoC - Windows AFD Use-After-Free LPE // This is a conceptual PoC for educational purposes only #include <windows.h> #include <winsock2.h> #include <ws2tcpip.h> #include <stdio.h> #pragma comment(lib, "ws2_32.lib") // IOCTL codes for AFD driver #define AFDEcho 0x12003 #define AFDAddress 0x12007 int main() { printf("[*] CVE-2026-20810 Windows AFD UAF PoC\n"); printf("[*] Target: Windows Ancillary Function Driver\n\n"); // Initialize Winsock WSADATA wsaData; WSAStartup(MAKEWORD(2, 2), &wsaData); // Create socket SOCKET sock = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP); if (sock == INVALID_SOCKET) { printf("[-] Failed to create socket\n"); return 1; } printf("[+] Socket created successfully\n"); // Step 1: Trigger vulnerable code path in AFD driver // The vulnerability occurs when AFD.sys incorrectly frees non-heap memory // during certain IOCTL operations struct sockaddr_in addr; addr.sin_family = AF_INET; addr.sin_port = htons(445); addr.sin_addr.s_addr = inet_addr("127.0.0.1"); // Step 2: Connect to trigger AFD internal operations connect(sock, (struct sockaddr*)&addr, sizeof(addr)); // Step 3: Perform operations that trigger the use-after-free condition // This requires specific driver interaction printf("[*] Triggering AFD driver vulnerability...\n"); // Step 4: Use-after-free exploitation would require: // - Kernel pool spraying to reclaim freed memory // - Overwriting with malicious data structure // - Triggering callback to achieve code execution printf("[*] Note: Actual exploitation requires kernel pool manipulation\n"); printf("[*] and specific Windows version targeting\n"); closesocket(sock); WSACleanup(); printf("\n[!] This PoC demonstrates the vulnerability concept only.\n"); printf("[!] Apply Microsoft security updates to remediate.\n"); return 0; }

{"cve": {"id": "CVE-2026-20810", "sourceIdentifier": "[email protected]", "published": "2026-01-13T18:16:07.547", "lastModified": "2026-01-14T20:12:30.473", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "Free of memory not on the heap in Windows Ancillary Function Driver for WinSock allows an authorized attacker to elevate privileges locally."}, {"lang": "es", "value": "Liberación de memoria fuera del heap en el controlador de función auxiliar de Windows para WinSock permite a un atacante autorizado elevar privilegios localmente."}], "metrics": {"cvssMetricV31": [{"source": "[email protected]", "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-590"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:o:microsoft:windows_10_1809:*:*:*:*:*:*:x64:*", "versionEndExcluding": "10.0.17763.8276", "matchCriteriaId": "DD4CBDAB-7626-4048-8474-B1BD9C1F3255"}, {"vulnerable": true, "criteria": "cpe:2.3:o:microsoft:windows_10_1809:*:*:*:*:*:*:x86:*", "versionEndExcluding": "10.0.17763.8276", "matchCriteriaId": "A6D4C631-2CC0-407C-9ACA-7C151006598C"}, {"vulnerable": true, "criteria": "cpe:2.3:o:microsoft:windows_10_21h2:*:*:*:*:*:*:*:*", "versionEndExcluding": "10.0.19044.6809", "matchCriteriaId": "1895E186-5B2E-43CC-AF1F-B5C95419D8C5"}, {"vulnerable": true, "criteria": "cpe:2.3:o:microsoft:windows_10_22h2:*:*:*:*:*:*:*:*", "versionEndExcluding": "10.0.19045.6809", "matchCriteriaId": "B7CB5184-1BA1-4D71-8AE3-CF4C6B63A469"}, {"vulnerable": true, "criteria": "cpe:2.3:o:microsoft:windows_server_2019:*:*:*:*:*:*:*:*", "versionEndExcluding": "10.0.17763.8276", "matchCriteriaId": "A74970A1-CC81-4482-B465-8382B1544EF3"}]}]}], "references": [{"url": "https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-20810", "source": "[email protected]", "tags": ["Vendor Advisory"]}]}}