CVE-2023-0996 in libheif
Summary
by MITRE • 02/24/2023
There is a vulnerability in the strided image data parsing code in the emscripten wrapper for libheif. An attacker could exploit this through a crafted image file to cause a buffer overflow in linear memory during a memcpy call.
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Analysis
by VulDB Data Team • 11/08/2024
The vulnerability identified as CVE-2023-0996 resides within the emscripten wrapper implementation for the libheif library, specifically targeting the strided image data parsing functionality. This issue manifests as a buffer overflow condition that occurs during memory operations when processing specially crafted image files. The emscripten environment serves as a compilation target that translates c and c++ code into webassembly, enabling high-performance applications to run in web browsers. The libheif library itself is designed for handling heif image format files, which are based on the high efficiency image format standard that provides superior compression compared to traditional formats like jpeg.
The technical flaw stems from inadequate bounds checking within the strided image data parsing code where the application fails to properly validate the size and structure of incoming image data before performing memory operations. When a maliciously constructed image file is processed, the parsing routine attempts to copy data into linear memory using memcpy without sufficient validation of the source buffer size relative to the destination buffer capacity. This fundamental oversight creates a condition where attacker-controlled data can overwrite adjacent memory locations, potentially leading to arbitrary code execution or application crashes. The vulnerability specifically affects the emscripten compilation environment which introduces additional complexity in memory management and data handling compared to native implementations.
The operational impact of this vulnerability extends beyond simple application instability to potentially enable remote code execution within the context of applications using the affected library. Since emscripten applications can be deployed in web browsers, an attacker could craft a malicious heif image file that when opened by a vulnerable application could lead to complete system compromise. The buffer overflow condition can be exploited to overwrite critical memory structures, function pointers, or return addresses, allowing for privilege escalation or code injection attacks. This vulnerability particularly affects web applications that process user-uploaded image files or any application that leverages the emscripten-compiled libheif library for heif image handling.
Mitigation strategies for CVE-2023-0996 should prioritize immediate patching of affected emscripten wrapper implementations and libheif library versions. Organizations should implement strict input validation and sanitization for all image file processing pipelines, particularly when dealing with user-uploaded content. The fix should include comprehensive bounds checking in the strided image data parsing code to ensure that memcpy operations only occur when source and destination buffer sizes are compatible. Additionally, deployment of address space layout randomization and stack canaries can provide additional defense-in-depth measures. This vulnerability aligns with CWE-121, heap-based buffer overflow, and maps to ATT&CK technique T1059.007 for command and scripting interpreter, as exploitation could enable arbitrary code execution through memory corruption. Security teams should also consider implementing network-based intrusion detection systems to monitor for exploitation attempts involving crafted heif image files, as the attack surface expands to web applications and browser-based environments where emscripten applications are deployed.