CVE-2013-0876 in FFmpeg
Summary
by MITRE
Multiple integer overflows in the (1) old_codec37 and (2) old_codec47 functions in libavcodec/sanm.c in FFmpeg before 1.1.3 allow remote attackers to have an unspecified impact via crafted LucasArts Smush data, which triggers an out-of-bounds array access.
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Analysis
by VulDB Data Team • 05/04/2018
The vulnerability identified as CVE-2013-0876 represents a critical security flaw within the FFmpeg multimedia processing library that affects versions prior to 1.1.3. This issue manifests in two distinct functions within the sanm.c file namely old_codec37 and old_codec47 which are responsible for handling LucasArts Smush video format decoding. The vulnerability stems from improper input validation and arithmetic handling within these legacy codec implementations that process specific multimedia data streams. Attackers can exploit this weakness by crafting malicious LucasArts Smush data that, when processed by the vulnerable FFmpeg library, triggers integer overflow conditions during array boundary calculations.
The technical implementation of this vulnerability involves integer overflows occurring in the mathematical operations used to determine array indices and buffer sizes within the codec processing functions. When the malicious data is parsed, the integer overflow causes the calculated array access indices to exceed valid memory boundaries, resulting in out-of-bounds memory access patterns. This type of vulnerability falls under the CWE-190 category of Integer Overflow or Wraparound, which is classified as a fundamental flaw in arithmetic operations that can lead to memory corruption and potential code execution. The specific nature of the flaw in FFmpeg's legacy codec handling demonstrates how older multimedia format support can introduce security risks when not properly validated against malicious inputs.
The operational impact of this vulnerability extends beyond simple memory corruption as it creates potential attack vectors for remote exploitation. When a system processes multimedia content using the vulnerable FFmpeg library, an attacker can craft specially formatted LucasArts Smush files that will trigger the integer overflow condition during playback or processing. This could lead to arbitrary code execution, denial of service conditions, or information disclosure depending on the specific execution environment and memory layout. The vulnerability is particularly concerning because LucasArts Smush format is a legacy video format that may still be encountered in older game content, archived media, or legacy systems that have not been updated to patched versions.
The attack surface for this vulnerability is significant given FFmpeg's widespread adoption across numerous multimedia applications, content management systems, and media processing platforms. Any application that relies on FFmpeg for video decoding, including web browsers, media players, content management systems, and streaming services, could be potentially compromised if they process untrusted multimedia content through the vulnerable codec functions. The exploitability of this vulnerability is enhanced by the fact that it requires minimal user interaction beyond viewing or processing the malicious content, making it particularly dangerous in automated processing scenarios or when content is automatically downloaded and rendered. Security researchers have categorized this vulnerability under ATT&CK technique T1203, which involves the exploitation of input validation flaws in multimedia processing components.
Mitigation strategies for CVE-2013-0876 primarily involve upgrading to FFmpeg version 1.1.3 or later where the integer overflow conditions have been addressed through proper input validation and boundary checking mechanisms. Organizations should conduct comprehensive vulnerability assessments to identify all systems and applications that rely on vulnerable FFmpeg versions and implement immediate patching procedures. Additional protective measures include implementing strict content validation for multimedia inputs, deploying sandboxing mechanisms for multimedia processing, and establishing network segmentation to limit potential attack vectors. Security monitoring should be enhanced to detect unusual processing patterns that might indicate exploitation attempts, while access controls should be strengthened to prevent unauthorized content upload or processing in sensitive environments. The remediation process must also include thorough testing of patched systems to ensure that the vulnerability is completely resolved without introducing regressions in multimedia processing functionality.