CVE-2008-1686 in libfishsound
Summary
by MITRE
Array index vulnerability in Speex 1.1.12 and earlier, as used in libfishsound 0.9.0 and earlier, including Illiminable DirectShow Filters and Annodex Plugins for Firefox, xine-lib before 1.1.12, and many other products, allows remote attackers to execute arbitrary code via a header structure containing a negative offset, which is used to dereference a function pointer.
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Analysis
by VulDB Data Team • 06/01/2025
The CVE-2008-1686 vulnerability represents a critical array index error that affects multiple multimedia processing libraries and applications. This flaw exists within the Speex audio codec implementation where improper validation of header structures leads to unpredictable behavior during function pointer dereferencing operations. The vulnerability specifically manifests when processing malformed audio files that contain negative offset values in their header structures, creating a condition where attackers can manipulate memory access patterns to execute arbitrary code on affected systems.
The technical root cause of this vulnerability stems from inadequate input validation within the Speex decoding routines, particularly in how the software handles header field parsing. When the decoder encounters a negative offset value, it fails to properly validate the bounds of array indexing operations, leading to a classic buffer underflow condition. This flaw maps directly to CWE-129, which describes improper validation of array indices, and CWE-787, which covers out-of-bounds write operations. The vulnerability operates at the intersection of memory safety and input validation, where the absence of proper boundary checks allows attackers to manipulate the execution flow through carefully crafted malicious audio files.
From an operational perspective, this vulnerability presents significant risk across numerous multimedia applications and plugins that utilize Speex decoding capabilities. The affected ecosystem includes libfishsound libraries, Illiminable DirectShow Filters, Annodex Plugins for Firefox, and xine-lib versions prior to 1.1.12, creating a wide attack surface that extends across different operating systems and media players. Attackers can exploit this vulnerability by crafting specially formatted audio files that, when processed by vulnerable applications, trigger the out-of-bounds memory access and subsequent code execution. This attack vector aligns with ATT&CK technique T1203, which describes exploitation of software vulnerabilities for privilege escalation and persistent access.
The impact of successful exploitation extends beyond simple code execution to potential system compromise, as attackers can leverage this vulnerability to gain unauthorized access to affected systems. The vulnerability's remote exploitability means that attackers do not require physical access to target systems, making it particularly dangerous in web-based scenarios where users might unknowingly download and play malicious audio files. Organizations using affected software should prioritize immediate patching and implementation of network segmentation to limit potential attack vectors. The vulnerability demonstrates the importance of robust input validation and memory safety practices in multimedia processing libraries, as similar flaws have been identified in other codec implementations throughout the industry.
Mitigation strategies should include immediate deployment of patches released by affected vendors, implementation of network-based intrusion detection systems to monitor for exploitation attempts, and application whitelisting to prevent execution of untrusted multimedia content. Security teams should also consider implementing sandboxing mechanisms for multimedia processing applications and conducting thorough vulnerability assessments of all systems utilizing Speex-based libraries. The vulnerability serves as a reminder of the critical importance of maintaining up-to-date multimedia libraries and implementing comprehensive security testing procedures for all third-party components used in media processing applications.