CVE-2008-2109 in libid3tag
Summary
by MITRE
field.c in the libid3tag 0.15.0b library allows context-dependent attackers to cause a denial of service (CPU consumption) via an ID3_FIELD_TYPE_STRINGLIST field that ends in \0 , which triggers an infinite loop.
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Analysis
by VulDB Data Team • 07/31/2021
The vulnerability identified as CVE-2008-2109 resides within the libid3tag 0.15.0b library, a widely used component for handling ID3 metadata in audio files, particularly mp3 files. This library serves as a critical dependency for numerous media applications and systems that process audio metadata, making the vulnerability particularly concerning from a security perspective. The flaw manifests in the field.c file where the library processes ID3_FIELD_TYPE_STRINGLIST fields, which are specifically designed to handle string lists within ID3 tags. The vulnerability represents a classic case of improper input validation and lacks proper boundary checking mechanisms that would prevent maliciously crafted data from causing unexpected behavior in the processing logic.
The technical flaw occurs when the library encounters an ID3_FIELD_TYPE_STRINGLIST field that terminates with a null character . This specific byte sequence triggers an infinite loop within the parsing routine because the library's implementation fails to properly handle the termination condition for string list processing. The parsing algorithm enters a state where it continuously iterates through the string list without making progress toward a proper termination, consuming excessive CPU resources and ultimately leading to a denial of service condition. This type of vulnerability falls under the category of resource exhaustion attacks, where the attacker can cause legitimate system resources to be consumed to the point of system instability or complete unresponsiveness. The vulnerability is context-dependent because it requires specific conditions to be met in the input data structure, making it more difficult to exploit but still potentially dangerous in environments where the library processes untrusted input.
The operational impact of this vulnerability extends beyond simple denial of service, as it can affect any application or system that relies on libid3tag for ID3 metadata processing. When exploited, the infinite loop consumes CPU cycles continuously, potentially leading to system performance degradation or complete system lockup depending on the scale of the attack. Applications that process large numbers of audio files, streaming services, media servers, and digital audio workstations could all be affected by this vulnerability. The vulnerability is particularly concerning because it can be triggered by simply processing a maliciously crafted audio file, making it a potential vector for remote denial of service attacks against systems that automatically process user-uploaded content. From an attack perspective, this vulnerability aligns with the ATT&CK framework's resource exhaustion technique where attackers leverage software flaws to consume system resources. The vulnerability also maps to CWE-835, which specifically addresses infinite loops or other forms of unbounded iterations that can lead to resource exhaustion.
Mitigation strategies for CVE-2008-2109 should focus on both immediate remediation and long-term architectural improvements. The most effective immediate solution involves upgrading to a newer version of libid3tag where the vulnerability has been patched, as the original version 0.15.0b contains the flawed implementation that allows the infinite loop to occur. Organizations should also implement input validation measures that check for malformed ID3 tags before processing them through the vulnerable library, which can provide an additional layer of protection. Additionally, systems should implement resource monitoring and limiting mechanisms to prevent a single process from consuming excessive CPU resources, which can help contain the impact of such attacks even when they occur. From a defensive standpoint, the vulnerability highlights the importance of proper boundary checking and input validation in cryptographic and media processing libraries, as these components often become targets for attackers seeking to exploit resource exhaustion vulnerabilities. The ATT&CK framework would categorize this vulnerability as part of the privilege escalation and resource exhaustion categories, where attackers can leverage software flaws to consume system resources and potentially cause broader system instability.