CVE-2014-2099 in FFmpeg
Summary
by MITRE
The msrle_decode_frame function in libavcodec/msrle.c in FFmpeg before 2.1.4 does not properly calculate line sizes, which allows remote attackers to cause a denial of service (out-of-bounds array access) or possibly have unspecified other impact via crafted Microsoft RLE video data.
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Analysis
by VulDB Data Team • 04/12/2025
The vulnerability identified as CVE-2014-2099 represents a critical flaw in the FFmpeg multimedia framework's handling of Microsoft RLE video format decoding. This issue resides within the msrle_decode_frame function located in libavcodec/msrle.c, where improper calculation of line sizes creates exploitable conditions that can be leveraged by remote attackers. The vulnerability affects FFmpeg versions prior to 2.1.4, making it a significant concern for systems that rely on this widely-used multimedia processing library for video decoding operations. The flaw specifically manifests when processing crafted Microsoft RLE video data, which can trigger unexpected behavior in the decoding pipeline.
The technical root cause of this vulnerability stems from inadequate bounds checking and line size calculation logic within the MSRLE decoding routine. When FFmpeg processes Microsoft RLE encoded video streams, it calculates the required line buffer sizes based on header information contained within the video data. However, the msrle_decode_frame function fails to properly validate or compute these line sizes, allowing maliciously crafted input to specify line dimensions that exceed allocated buffer boundaries. This improper calculation creates a scenario where subsequent array access operations reference memory locations beyond the intended buffer limits, resulting in out-of-bounds memory access conditions. The vulnerability can potentially be exploited to trigger memory corruption, leading to application crashes or more severe consequences depending on the execution context.
The operational impact of CVE-2014-2099 extends beyond simple denial of service, as the vulnerability may enable more sophisticated attacks depending on the system configuration and execution environment. Remote attackers who can influence video input processing through network-based attacks or malicious file delivery mechanisms can exploit this flaw to cause service disruption by forcing application crashes or resource exhaustion. Additionally, the unspecified other impacts mentioned in the vulnerability description suggest potential for more severe consequences including information disclosure or privilege escalation scenarios, particularly when FFmpeg is used in server environments or applications with elevated privileges. This makes the vulnerability particularly dangerous in web applications, media processing servers, or any system where FFmpeg handles untrusted video input from external sources.
Mitigation strategies for CVE-2014-2099 primarily focus on upgrading to patched versions of FFmpeg where the line size calculation logic has been corrected and enhanced with proper bounds checking mechanisms. System administrators should prioritize updating FFmpeg installations to version 2.1.4 or later, which includes the necessary fixes for this vulnerability. Additionally, implementing input validation measures such as strict file format verification, size limiting for video streams, and sandboxing of multimedia processing components can provide additional protective layers. Network-based mitigations should include filtering of Microsoft RLE video content at perimeter defenses, while application-level protections can involve implementing robust error handling and memory protection mechanisms. The vulnerability aligns with CWE-129, which addresses improper validation of array index values, and may map to ATT&CK technique T1203, focusing on exploitation of input validation vulnerabilities in multimedia processing systems. Organizations should also consider implementing monitoring for abnormal application behavior or resource consumption patterns that may indicate exploitation attempts.