CVE-2016-7562 in FFmpeg
Summary
by MITRE
The ff_draw_pc_font function in libavcodec/cga_data.c in FFmpeg before 3.1.4 allows remote attackers to cause a denial of service (buffer overflow) via a crafted AVI file.
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Analysis
by VulDB Data Team • 07/15/2019
The vulnerability identified as CVE-2016-7562 represents a critical buffer overflow flaw within the FFmpeg multimedia framework that affects versions prior to 3.1.4. This issue resides in the ff_draw_pc_font function located in the libavcodec/cga_data.c file, which is part of FFmpeg's extensive codec library designed to handle various multimedia formats including AVI files. The flaw specifically manifests when processing crafted AVI files that contain malformed graphics data, creating a scenario where remote attackers can exploit this vulnerability to disrupt system operations without requiring local access or elevated privileges.
The technical exploitation of this vulnerability occurs through a classic buffer overflow condition where the ff_draw_pc_font function fails to properly validate input data dimensions when rendering PC font graphics within AVI containers. When a malicious AVI file contains oversized or malformed font data structures, the function attempts to write beyond allocated memory boundaries, potentially causing memory corruption that leads to application crashes or unpredictable behavior. This type of vulnerability falls under CWE-121, which categorizes buffer overflow conditions where insufficient bounds checking allows attackers to overwrite adjacent memory locations, and aligns with ATT&CK technique T1059.007 for execution through multimedia processing components.
The operational impact of this vulnerability extends beyond simple denial of service, as it creates potential pathways for more sophisticated attacks within multimedia processing environments. Systems that process untrusted AVI files through FFmpeg libraries, including media servers, content management systems, and multimedia applications, become vulnerable to remote exploitation. Attackers can craft malicious AVI files that trigger the buffer overflow during normal playback or processing operations, leading to service disruption for legitimate users. The vulnerability's remote exploitability means that attackers do not need physical access to target systems, making it particularly dangerous in web-based or networked environments where multimedia content is frequently processed.
Mitigation strategies for CVE-2016-7562 primarily focus on immediate software updates and system hardening measures. Organizations should prioritize upgrading to FFmpeg version 3.1.4 or later, which includes patches specifically addressing the buffer overflow condition in the ff_draw_pc_font function. Additionally, implementing input validation controls at network boundaries can help filter potentially malicious AVI files before they reach systems running FFmpeg. Network administrators should consider deploying content filtering solutions that can identify and block suspicious multimedia files, while application developers should ensure that their FFmpeg-based applications implement proper error handling and input sanitization routines. Security monitoring should include detection of abnormal process termination patterns and memory access violations that may indicate exploitation attempts, as these behaviors often precede successful attacks against multimedia processing components.