CVE-2017-11735 in libvorbis
Summary
by MITRE
The vorbis_block_clear function in lib/block.c in Xiph.Org libvorbis 1.3.5 allows remote attackers to cause a denial of service (NULL pointer dereference and application crash) via a crafted ogg file.
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Analysis
by VulDB Data Team • 12/16/2024
The vulnerability identified as CVE-2017-11735 resides within the libvorbis library version 1.3.5, specifically within the vorbis_block_clear function located in the lib/block.c source file. This flaw represents a critical security issue that enables remote attackers to execute denial of service attacks against systems processing Ogg audio files. The vulnerability manifests when the library encounters malformed or crafted Ogg files that trigger a NULL pointer dereference during the cleanup phase of audio block processing, resulting in application crashes and service unavailability.
The technical implementation of this vulnerability stems from insufficient input validation and error handling within the vorbis_block_clear function. When processing maliciously constructed Ogg files, the function fails to properly validate pointer references before attempting to dereference them, creating a condition where a NULL pointer is accessed during the cleanup routine. This type of flaw falls under the Common Weakness Enumeration category CWE-476, which specifically addresses NULL pointer dereference vulnerabilities. The vulnerability is particularly dangerous because it can be exploited remotely through any application that utilizes libvorbis for audio file processing, including media players, streaming services, and content management systems.
The operational impact of CVE-2017-11735 extends beyond simple application crashes to encompass broader system availability risks. Attackers can craft Ogg files that, when processed by vulnerable applications, will cause immediate service disruption and potential system instability. This vulnerability affects a wide range of software ecosystems including web browsers, media players, streaming platforms, and multimedia applications that depend on the libvorbis library for audio decoding. The attack vector is particularly concerning as it requires no special privileges or user interaction beyond the mere act of opening or processing the malicious file, making it a high-risk vulnerability for widespread exploitation.
Mitigation strategies for this vulnerability involve immediate patching of affected libvorbis installations to version 1.3.6 or later, which contains the necessary fixes to prevent the NULL pointer dereference condition. System administrators should prioritize updating all applications that utilize libvorbis, particularly those handling user-uploaded content or external media files. Additional protective measures include implementing input validation and sanitization for all Ogg file processing, deploying network-based intrusion detection systems to monitor for suspicious file patterns, and establishing robust application sandboxing to limit the impact of potential exploitation. The vulnerability demonstrates the importance of proper error handling and input validation in multimedia processing libraries, aligning with ATT&CK technique T1499.004 which addresses network denial of service attacks through application-level vulnerabilities. Organizations should also consider implementing automated vulnerability scanning processes to identify and remediate similar issues across their software infrastructure.