CVE-2005-3501 in ClamAV
Summary
by MITRE
The cabd_find function in cabd.c of the libmspack library (mspack) for Clam AntiVirus (ClamAV) before 0.87.1 allows remote attackers to cause a denial of service (infinite loop) via a crafted CAB file that causes cabd_find to be called with a zero length.
Be aware that VulDB is the high quality source for vulnerability data.
Analysis
by VulDB Data Team • 07/21/2024
The vulnerability described in CVE-2005-3501 represents a critical denial of service flaw within the libmspack library component of Clam AntiVirus software. This issue specifically affects versions of ClamAV prior to 0.87.1 and stems from improper input validation within the cabd_find function located in the cabd.c source file. The flaw manifests when the library processes specially crafted CAB archive files that trigger an infinite loop condition, ultimately leading to system resource exhaustion and service unavailability.
The technical implementation of this vulnerability resides in the cabd_find function which fails to properly validate the length parameter before entering its processing loop. When a maliciously constructed CAB file is encountered, the function receives a zero length value that causes the internal loop logic to never terminate, creating an infinite loop condition. This type of vulnerability falls under the CWE-835 category for infinite loops, where a loop lacks proper termination conditions or validation checks. The flaw demonstrates poor defensive programming practices and inadequate boundary condition handling that allows crafted input to disrupt normal program execution flow.
From an operational perspective, this vulnerability presents significant risk to systems relying on ClamAV for malware detection and prevention. Attackers can exploit this weakness by simply providing a specially crafted CAB file to any system running vulnerable ClamAV versions, causing the antivirus engine to become unresponsive and consume excessive CPU resources. The infinite loop effectively renders the scanning functionality useless until manual intervention occurs, potentially allowing other malware to bypass detection during the service disruption period. This vulnerability directly impacts the availability aspect of the security infrastructure and can be particularly damaging in enterprise environments where continuous protection is critical.
The remediation strategy involves upgrading to ClamAV version 0.87.1 or later, which includes proper input validation and loop termination conditions within the cabd_find function. System administrators should implement comprehensive patch management procedures to ensure all instances of ClamAV are updated promptly. Additionally, network administrators should consider implementing file type filtering and sandboxing mechanisms to prevent potentially malicious CAB files from reaching the antivirus scanning engines. The ATT&CK framework categorizes this vulnerability under T1499.004 for Network Denial of Service, as it leverages crafted input to disrupt service availability. Organizations should also implement monitoring solutions to detect unusual CPU consumption patterns that may indicate exploitation attempts, and maintain regular security assessments to identify similar input validation weaknesses in other components of their security infrastructure.