CVE-2017-9995 in FFmpeg
Summary
by MITRE
libavcodec/scpr.c in FFmpeg 3.3 before 3.3.1 does not properly validate height and width data, which 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 file.
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Analysis
by VulDB Data Team • 12/09/2022
The vulnerability identified as CVE-2017-9995 resides within the FFmpeg media processing library, specifically in the scpr.c file that handles SCPR (SMPTE 390) codec decoding operations. This issue affects FFmpeg versions 3.3 and earlier, with the vulnerability being resolved in version 3.3.1. The flaw represents a classic buffer overflow condition that occurs when the library fails to properly validate dimensional parameters during media file parsing, creating a critical security gap that can be exploited remotely.
The technical implementation of this vulnerability stems from insufficient input validation within the video codec decoding pipeline. When FFmpeg processes a crafted media file containing malformed height and width parameters, the scpr.c component attempts to allocate heap memory based on these unvalidated dimensions without proper bounds checking. This inadequate validation allows attackers to specify dimensions that exceed the allocated buffer space, resulting in heap corruption. The vulnerability manifests as a heap-based buffer overflow that can trigger application crashes or potentially enable more sophisticated exploitation techniques depending on the execution environment and memory layout.
The operational impact of this vulnerability extends beyond simple denial of service conditions, as it represents a potential pathway for more serious security compromises. Remote attackers can craft malicious media files that, when processed by vulnerable FFmpeg implementations, will cause system instability and potential application crashes. This affects a wide range of applications and systems that rely on FFmpeg for media processing, including web servers, media streaming platforms, content management systems, and multimedia applications. The vulnerability's remote exploitability means that attackers can trigger the condition without requiring local access to the target system, making it particularly dangerous in web-facing environments where media files are processed automatically.
The security implications of CVE-2017-9995 align with CWE-121, which describes heap-based buffer overflow conditions, and can be mapped to ATT&CK technique T1203, representing exploitation of remote services through malformed input. Organizations using FFmpeg in their media processing pipelines face significant risk exposure, particularly those that automatically process user-uploaded content or handle media files from untrusted sources. The vulnerability demonstrates the critical importance of proper input validation in multimedia processing libraries, where malformed data can lead to memory corruption and system instability. This flaw underscores the necessity for comprehensive security testing of media libraries and the implementation of robust input sanitization mechanisms to prevent similar issues in other components of the software supply chain.
Mitigation strategies for this vulnerability require immediate patching of affected FFmpeg installations to version 3.3.1 or later, which includes proper validation of height and width parameters during SCPR codec processing. Organizations should also implement additional defensive measures such as input sanitization, content filtering, and restricted processing of untrusted media files. Network-level protections including media file validation at ingress points and sandboxed processing environments can provide additional layers of defense. Regular security assessments of media processing pipelines and adherence to secure coding practices in multimedia libraries remain essential for preventing similar vulnerabilities from emerging in future implementations.