CVE-2014-8549 in FFmpeg
Summary
by MITRE
libavcodec/on2avc.c in FFmpeg before 2.4.2 does not constrain the number of channels to at most 2, which allows remote attackers to cause a denial of service (out-of-bounds access) or possibly have unspecified other impact via crafted On2 data.
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Analysis
by VulDB Data Team • 02/24/2022
The vulnerability identified as CVE-2014-8549 resides within the FFmpeg multimedia framework's handling of On2 video codec data through the libavcodec/on2avc.c component. This flaw represents a classic buffer over-read condition that occurs when the software fails to properly validate input parameters during video decoding operations. The vulnerability specifically affects FFmpeg versions prior to 2.4.2, making it a significant concern for systems that rely on older multimedia processing libraries. The issue stems from insufficient input validation where the software does not enforce a maximum channel limit of two during On2 data processing, creating a potential attack surface for remote adversaries.
The technical implementation of this vulnerability involves the improper handling of audio channel specifications within the On2 video codec parser. When FFmpeg encounters crafted On2 data containing an excessive number of audio channels beyond the expected two-channel limit, the decoder attempts to access memory locations that are not properly allocated for the additional channels. This out-of-bounds memory access can result in unpredictable behavior including application crashes, memory corruption, or potentially more severe consequences depending on the execution environment. The flaw operates at the boundary between input validation and memory management, where the absence of proper bounds checking allows malicious data to traverse allocated memory regions. This type of vulnerability aligns with CWE-129, which specifically addresses insufficient input validation leading to out-of-bounds access conditions.
From an operational perspective, this vulnerability presents a remote denial of service threat that can be exploited through crafted multimedia content delivered via various attack vectors including web browsers, email attachments, or multimedia streaming platforms. The impact extends beyond simple service disruption as the out-of-bounds memory access could potentially be leveraged for more sophisticated attacks depending on the target environment and memory layout. Attackers can construct malicious On2 video files that, when processed by vulnerable FFmpeg implementations, trigger the exploitable condition. The vulnerability's remote nature makes it particularly dangerous as it requires no local access or user interaction beyond viewing or processing the malicious content. Systems that process multimedia content from untrusted sources, including media servers, content delivery networks, and web applications, face significant risk exposure.
The mitigation strategy for CVE-2014-8549 centers on immediate software updates to FFmpeg version 2.4.2 or later, which contain the necessary patches to enforce proper channel limits during On2 data processing. Organizations should conduct comprehensive vulnerability assessments to identify all systems running vulnerable FFmpeg versions and prioritize their remediation. Network segmentation and content filtering mechanisms can provide additional defensive layers by blocking suspicious multimedia content before it reaches systems running FFmpeg. Security monitoring should include detection of unusual memory access patterns and process crashes that might indicate exploitation attempts. The vulnerability demonstrates the importance of robust input validation in multimedia processing libraries and highlights the need for continuous security updates in open-source software components. Implementation of the ATT&CK framework's defense-in-depth principles recommends multiple layers of protection including software patching, network monitoring, and application sandboxing to prevent exploitation of similar vulnerabilities.