CVE-2016-9822 in libav
Summary
by MITRE
Integer overflow in libavcodec/mpeg12dec.c in libav 11.8 allows remote attackers to cause a denial of service (crash) via a crafted file.
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Analysis
by VulDB Data Team • 09/03/2020
The vulnerability identified as CVE-2016-9822 represents a critical integer overflow flaw within the libav multimedia framework version 11.8, specifically affecting the MPEG-1 and MPEG-2 decoder components. This issue resides in the libavcodec/mpeg12dec.c source file where improper handling of integer values during video decoding processes creates a condition that can be exploited by remote attackers to trigger system instability. The flaw manifests when processing specially crafted media files that contain malformed data structures, leading to arithmetic overflow conditions that ultimately result in application crashes.
The technical nature of this vulnerability stems from inadequate input validation and boundary checking within the MPEG-1 and MPEG-2 video decoding routines. When the decoder encounters malformed header information or frame dimensions in crafted media files, the integer variables used to calculate buffer sizes or frame dimensions exceed their maximum representable values, causing unsigned integer overflow. This overflow condition results in the allocation of insufficient memory buffers or incorrect frame size calculations, which subsequently leads to memory corruption and program termination. The vulnerability is particularly concerning because it can be triggered remotely through the processing of maliciously formatted media files without requiring any special privileges or user interaction beyond opening the file.
From an operational perspective, this vulnerability presents significant risks to systems that rely on libav for video processing, including media servers, content delivery networks, and multimedia applications. The denial of service impact means that legitimate users may be unable to access video content or services that depend on the vulnerable software, potentially causing widespread disruption. Attackers can leverage this flaw to systematically crash video processing servers, rendering them unavailable to legitimate users and potentially enabling more sophisticated attacks if combined with other vulnerabilities. The remote exploitability aspect means that attackers do not need physical access to the target system, making this vulnerability particularly dangerous in networked environments where media files may be processed automatically or through web applications.
The vulnerability maps to CWE-190, which specifically addresses integer overflow conditions, and aligns with several ATT&CK techniques including T1499.004 for network denial of service and T1059 for command and scripting interpreter usage. Organizations using libav versions prior to 11.9 should immediately implement mitigations including updating to patched versions, implementing strict input validation for media files, and deploying network segmentation to limit exposure. Additional protective measures include using sandboxed environments for media processing, implementing automated scanning for malicious media files, and establishing robust monitoring systems to detect potential exploitation attempts. The vulnerability also highlights the importance of proper integer overflow protection mechanisms in multimedia processing libraries, emphasizing the need for comprehensive testing including fuzzing and boundary condition validation in security-critical software components.