CVE-2017-9987 in libav
Summary
by MITRE
There is a heap-based buffer overflow in the function hpel_motion in mpegvideo_motion.c in libav 12.1. A crafted input can lead to a remote denial of service attack.
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Analysis
by VulDB Data Team • 12/09/2022
The vulnerability identified as CVE-2017-9987 represents a critical heap-based buffer overflow within the libav multimedia framework version 12.1 specifically affecting the hpel_motion function located in mpegvideo_motion.c. This flaw exists in the handling of motion estimation parameters during video decoding processes and constitutes a significant security risk that can be exploited remotely. The vulnerability falls under the Common Weakness Enumeration category of CWE-121, which describes heap-based buffer overflow conditions where insufficient boundary checking allows attackers to overwrite adjacent heap memory regions. The affected libav library serves as a foundational component for multimedia processing across numerous applications and systems, making this vulnerability particularly dangerous as it can be leveraged by malicious actors to disrupt services without requiring local system access.
The technical exploitation of this vulnerability occurs when a crafted malicious video file is processed by an application utilizing libav for multimedia handling. During the motion estimation phase of video decoding, the hpel_motion function fails to properly validate input parameters before performing memory operations that can lead to heap corruption. The buffer overflow manifests when the function attempts to write data beyond the allocated heap buffer boundaries, potentially overwriting adjacent memory structures including heap metadata, function pointers, or other critical data elements. This type of vulnerability aligns with ATT&CK technique T1203, which involves the exploitation of memory corruption vulnerabilities to achieve remote code execution or denial of service conditions. The vulnerability's remote exploitability stems from the fact that any application or service processing video content through libav can become a target, including web browsers, media servers, and multimedia applications.
The operational impact of CVE-2017-9987 extends beyond simple denial of service to potentially enable more sophisticated attacks depending on the target environment and system configuration. When exploited successfully, the buffer overflow can cause application crashes, system instability, or in some cases could be leveraged to achieve arbitrary code execution through careful exploitation of the heap corruption. The vulnerability affects a wide range of systems and applications that depend on libav for video processing, including but not limited to web applications, media streaming services, content management systems, and multimedia frameworks. Organizations utilizing affected software may experience service interruptions, data processing failures, or potential security breaches if the vulnerability is not properly addressed. The remote nature of the attack means that adversaries can target systems without physical access or local privileges, making this vulnerability particularly concerning for service providers and organizations with public-facing multimedia applications.
Mitigation strategies for CVE-2017-9987 primarily involve immediate patching of affected libav installations to the latest secure versions that contain fixes for the heap buffer overflow condition. System administrators should prioritize updating all applications and services that depend on libav, particularly those handling untrusted video content from external sources. Additionally, implementing input validation measures and sandboxing techniques can provide defense-in-depth protection against exploitation attempts. Network segmentation and access controls should be reinforced to limit potential attack vectors, while monitoring systems should be configured to detect unusual application behavior that might indicate exploitation attempts. Organizations should also consider implementing automated patch management systems to ensure timely deployment of security updates. The vulnerability serves as a reminder of the critical importance of maintaining up-to-date multimedia libraries and frameworks, as well as the necessity of conducting regular security assessments of multimedia processing components within complex software ecosystems.