CVE-2017-14734 in libbpg
Summary
by MITRE
The build_msps function in libbpg.c in libbpg 0.9.7 allows remote attackers to cause a denial of service (heap-based buffer overflow and application crash) or possibly have unspecified other impact via a crafted BPG file, related to hevc_decode_init1.
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Analysis
by VulDB Data Team • 11/19/2019
The vulnerability identified as CVE-2017-14734 represents a critical heap-based buffer overflow in the libbpg library version 0.9.7, specifically within the build_msps function located in libbpg.c. This flaw occurs during the processing of BPG (Better Portable Graphics) image files, which are designed to be a more efficient alternative to traditional image formats like jpeg and png. The vulnerability stems from inadequate input validation and memory management when handling the hevc_decode_init1 component, which is responsible for initializing HEVC (High Efficiency Video Coding) decoding parameters within the BPG file structure.
The technical implementation of this vulnerability involves the build_msps function failing to properly validate the size and structure of data elements within the BPG file header, particularly when processing HEVC-related metadata. When a maliciously crafted BPG file is processed, the function attempts to allocate memory on the heap based on malformed input values, resulting in a buffer overflow condition. This overflow can overwrite adjacent memory locations, leading to unpredictable behavior including application crashes, memory corruption, or potentially more severe consequences depending on the execution context. The vulnerability is classified as heap-based because the overflow occurs within heap-allocated memory regions rather than stack-based buffers, making it particularly challenging to exploit reliably.
From an operational perspective, this vulnerability presents significant risks to systems that process BPG image files, including web servers, image processing applications, and content management systems that accept user-uploaded images. Attackers can leverage this flaw by crafting specially designed BPG files that trigger the overflow when opened or processed by vulnerable applications. The impact extends beyond simple denial of service, as the memory corruption could potentially be exploited to execute arbitrary code, depending on the target system configuration and memory layout. This vulnerability affects a wide range of applications that depend on libbpg for image processing, including various multimedia frameworks and image manipulation tools.
Security professionals should prioritize immediate mitigation of this vulnerability through library updates, as the flaw exists in the widely used libbpg 0.9.7 release. The vulnerability aligns with CWE-121, heap-based buffer overflow, and represents a significant concern in the context of the ATT&CK framework under the T1203 technique for legitimate program execution, where attackers may attempt to leverage such memory corruption vulnerabilities for privilege escalation or code execution. Organizations should implement strict file validation and sanitization measures, particularly for user-uploaded content, and consider deploying web application firewalls or content filtering solutions that can detect and block malicious BPG files. Additionally, regular security audits of image processing pipelines and comprehensive vulnerability management programs should be implemented to prevent similar issues in other image processing libraries and multimedia frameworks that may share similar architectural patterns.