CVE-2017-9253 in Freeware Advanced Audio Decoder
Summary
by MITRE
The mp4ff_read_stsd function in common/mp4ff/mp4atom.c in Freeware Advanced Audio Decoder 2 (FAAD2) 2.7 allows remote attackers to cause a denial of service (large loop and CPU consumption) via a crafted mp4 file.
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Analysis
by VulDB Data Team • 10/21/2019
The vulnerability identified as CVE-2017-9253 resides within the Freeware Advanced Audio Decoder 2 version 2.7, specifically in the mp4ff_read_stsd function located in the common/mp4ff/mp4atom.c file. This flaw represents a classic denial of service vulnerability that can be exploited through carefully crafted mp4 media files. The issue manifests when the decoder processes malformed or specially constructed mp4 containers that contain excessive or malformed metadata structures, leading to abnormal processing behavior.
The technical root cause of this vulnerability stems from inadequate input validation within the mp4ff_read_stsd function which handles the parsing of sample description boxes in mp4 files. When processing a maliciously crafted mp4 file, the function enters into a large loop that consumes excessive CPU resources without proper bounds checking or loop termination conditions. This behavior aligns with CWE-835, which describes the weakness of a loop with an unlimited number of iterations, often resulting in resource exhaustion. The function fails to validate the size and structure of the sample description boxes before attempting to parse them, allowing attackers to manipulate the parsing logic through crafted file structures.
The operational impact of this vulnerability extends beyond simple service disruption to potentially affect systems running FAAD2 as a media processing component. Attackers can exploit this weakness by preparing and distributing specially crafted mp4 files that, when processed by vulnerable systems, cause significant CPU utilization spikes and system resource exhaustion. This can affect various applications including media players, streaming services, and content processing pipelines that rely on FAAD2 for audio decoding. The vulnerability is particularly concerning in environments where automated media processing occurs, as it can lead to cascading failures and system instability. From an ATT&CK perspective, this vulnerability maps to the T1499.004 technique involving network denial of service attacks, where the attacker leverages resource exhaustion to disrupt system availability.
Mitigation strategies for CVE-2017-9253 should focus on both immediate remediation and long-term architectural improvements. The most effective immediate solution involves upgrading to a patched version of FAAD2 where the mp4ff_read_stsd function has been modified to include proper bounds checking and loop termination conditions. Organizations should also implement input validation mechanisms at the application level to detect and reject suspicious mp4 file structures before they reach the vulnerable decoder component. Additionally, system administrators should consider implementing resource monitoring and rate limiting for media processing components to prevent a single malicious file from consuming excessive system resources. The fix should incorporate proper error handling and timeout mechanisms to ensure that even malformed input does not cause indefinite processing loops, aligning with defensive programming practices recommended in both CWE and secure coding standards.