CVE-2012-6618 in FFmpeg
Summary
by MITRE
The av_probe_input_buffer function in libavformat/utils.c in FFmpeg before 1.0.2, when running with certain -probesize values, allows remote attackers to cause a denial of service (crash) via a crafted MP3 file, possibly related to frame size or lack of sufficient "frames to estimate rate."
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Analysis
by VulDB Data Team • 01/18/2022
The vulnerability identified as CVE-2012-6618 represents a critical denial of service flaw within the FFmpeg multimedia framework that affects versions prior to 1.0.2. This issue resides in the av_probe_input_buffer function located in libavformat/utils.c, which serves as a fundamental component for detecting and processing various multimedia file formats. The vulnerability specifically manifests when FFmpeg processes MP3 files with certain probe size configurations, creating a condition where maliciously crafted audio files can trigger unexpected behavior in the media processing pipeline.
The technical root cause of this vulnerability stems from insufficient input validation and buffer handling within the frame size estimation algorithms. When FFmpeg encounters an MP3 file with specific characteristics, particularly those that manipulate the frame size or rate estimation parameters, the av_probe_input_buffer function fails to properly validate the input data before attempting to process it. This leads to a scenario where the function may attempt to access memory locations beyond the allocated buffer boundaries or perform calculations based on invalid frame size assumptions. The flaw is particularly dangerous because it operates at the probe stage, which occurs before any actual media decoding begins, making it possible for attackers to exploit this vulnerability even before the application attempts to play or process the media content.
The operational impact of CVE-2012-6618 extends beyond simple service disruption, as it represents a significant security risk for any system that relies on FFmpeg for media processing. Remote attackers can leverage this vulnerability to crash FFmpeg applications through crafted MP3 files, potentially affecting a wide range of software including media servers, content management systems, and multimedia processing applications. The vulnerability is particularly concerning in web-based applications where users can upload or stream media files, as it could enable attackers to systematically crash media processing services and potentially cause broader system instability. This type of denial of service attack can be executed without requiring any special privileges or authentication, making it a particularly attractive vector for malicious actors seeking to disrupt services.
This vulnerability aligns with CWE-129, which addresses improper validation of input boundaries, and demonstrates characteristics consistent with the ATT&CK technique T1499.004 for network denial of service. The flaw essentially creates a buffer overflow condition or memory access violation that results in application crashes, which can be amplified in environments where FFmpeg is used as a backend service for handling user-uploaded content. Organizations using FFmpeg in production environments should prioritize immediate patching to address this vulnerability, as the impact can be severe in scenarios involving automated media processing or streaming services where continuous availability is critical. The fix implemented in FFmpeg 1.0.2 involved enhanced input validation and more robust frame size estimation algorithms that prevent the exploitation of malformed MP3 files through proper boundary checking and input sanitization measures.