CVE-2017-14057 in FFmpeg
Summary
by MITRE
In FFmpeg 3.3.3, a DoS in asf_read_marker() due to lack of an EOF (End of File) check might cause huge CPU and memory consumption. When a crafted ASF file, which claims a large "name_len" or "count" field in the header but does not contain sufficient backing data, is provided, the loops over the name and markers would consume huge CPU and memory resources, since there is no EOF check inside these loops.
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Analysis
by VulDB Data Team • 12/27/2022
The vulnerability identified as CVE-2017-14057 represents a critical denial of service flaw within the FFmpeg multimedia framework version 3.3.3. This issue specifically affects the asf_read_marker() function which processes Advanced Systems Format files, a container format commonly used for digital audio and video content. The flaw stems from inadequate input validation and boundary checking mechanisms within the ASF file parser, creating a scenario where maliciously crafted files can trigger excessive resource consumption. The vulnerability manifests when an attacker constructs an ASF file containing inflated "name_len" or "count" fields in the file header that exceed the actual available data, leading to malformed processing behavior.
The technical root cause of this vulnerability lies in the absence of proper end-of-file checking within critical loops that iterate through marker and name data structures. When FFmpeg encounters such a crafted file, the parser enters infinite or extremely resource-intensive loops as it attempts to process the inflated count values without verifying whether sufficient data exists to satisfy these claims. This lack of bounds checking creates a condition where the software's memory allocation and CPU processing cycles become consumed disproportionately to the actual file content. The vulnerability maps directly to CWE-129, which addresses insufficient input validation, and CWE-772, which covers missing resource cleanup. The absence of EOF validation in these loops represents a classic example of unchecked iteration that can be exploited to exhaust system resources.
The operational impact of this vulnerability extends beyond simple service disruption to potentially enable resource exhaustion attacks that can affect system availability. When a vulnerable FFmpeg instance processes the malicious ASF file, it consumes massive CPU cycles and memory resources, potentially causing the application to become unresponsive or crash entirely. This behavior can be particularly dangerous in server environments where FFmpeg is used for media processing, as it could enable attackers to perform resource exhaustion attacks that impact legitimate users. The vulnerability affects systems processing ASF files through FFmpeg, including web servers, media processing applications, and content management systems that rely on FFmpeg for video and audio handling. This type of attack aligns with ATT&CK technique T1499.004, which covers resource exhaustion via file and directory manipulation, and represents a significant concern for organizations relying on multimedia processing capabilities.
Mitigation strategies for CVE-2017-14057 require immediate patching of FFmpeg installations to versions that include proper EOF checking and bounds validation. Organizations should implement input validation measures that verify file headers against actual data content before processing, particularly for files with variable-length fields. Network-based defenses can include content inspection systems that identify and block suspicious ASF files, while application-level protections should enforce resource limits on processing operations. System administrators should also consider implementing monitoring solutions that detect unusual CPU and memory consumption patterns that may indicate exploitation attempts. The fix typically involves adding proper bounds checking within the affected parsing loops to ensure that iteration counts do not exceed available data, preventing the resource exhaustion behavior that enables the denial of service condition. Regular security updates and vulnerability assessments should be maintained to prevent similar issues in other multimedia processing components that may exhibit similar parsing vulnerabilities.