CVE-2015-3417 in FFmpeg
Summary
by MITRE
Use-after-free vulnerability in the ff_h264_free_tables function in libavcodec/h264.c in FFmpeg before 2.3.6 allows remote attackers to cause a denial of service or possibly have unspecified other impact via crafted H.264 data in an MP4 file, as demonstrated by an HTML VIDEO element that references H.264 data.
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Analysis
by VulDB Data Team • 05/09/2022
The CVE-2015-3417 vulnerability represents a critical use-after-free flaw within the FFmpeg multimedia framework that affects versions prior to 2.3.6. This vulnerability resides in the ff_h264_free_tables function located in libavcodec/h264.c, which handles the cleanup of H.264 video decoding tables. The flaw manifests when processing maliciously crafted H.264 encoded data embedded within MP4 containers, making it particularly dangerous in web environments where multimedia content is frequently streamed through HTML VIDEO elements. The vulnerability is categorized under CWE-416 as a use-after-free condition, which occurs when a program continues to reference memory after it has been freed, potentially leading to unpredictable behavior and system instability.
The technical exploitation of this vulnerability requires an attacker to construct specially crafted H.264 video data that, when processed by the affected FFmpeg version, triggers the use-after-free condition during table cleanup operations. When a victim's system attempts to decode this malicious content, the memory management routines fail to properly handle the freed memory references, creating opportunities for denial of service attacks or potentially more severe consequences. The vulnerability's impact extends beyond simple service disruption since the use-after-free condition can be leveraged to execute arbitrary code or cause system crashes, depending on the specific memory layout and exploitation techniques employed by attackers. This type of vulnerability aligns with ATT&CK technique T1203, which involves exploitation of software vulnerabilities for privilege escalation or code execution.
The operational impact of CVE-2015-3417 is significant within multimedia processing environments, particularly those that handle untrusted video content from web applications or user-uploaded files. Systems using FFmpeg for video transcoding, streaming, or playback are at risk when processing MP4 files containing malicious H.264 data, as the vulnerability can be triggered through standard HTML VIDEO element references. Organizations deploying web applications that process multimedia content must consider the potential for remote code execution or service disruption when vulnerable FFmpeg versions are in use. The vulnerability demonstrates how multimedia frameworks can become attack vectors in modern web environments where rich media content is increasingly prevalent, making it essential for security teams to monitor and update their multimedia processing libraries regularly.
Mitigation strategies for CVE-2015-3417 primarily focus on upgrading to FFmpeg versions 2.3.6 or later, where the use-after-free vulnerability has been addressed through proper memory management implementation. System administrators should implement comprehensive patch management processes to ensure all multimedia processing components are updated promptly, particularly in environments handling user-generated content or external video sources. Additional protective measures include implementing strict input validation for multimedia files, deploying content filtering solutions that can detect and block suspicious H.264 data patterns, and establishing network segmentation to limit the impact of potential exploitation attempts. Security monitoring should include detection of unusual memory access patterns or process crashes that might indicate exploitation attempts, while also maintaining awareness of related vulnerabilities in multimedia frameworks that could compound the risk profile of affected systems.