CVE-2005-2056 in ClamAV
Summary
by MITRE
The Quantum archive decompressor in Clam AntiVirus (ClamAV) before 0.86.1 allows remote attackers to cause a denial of service (application crash) via a crafted Quantum archive.
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Analysis
by VulDB Data Team • 07/05/2021
The vulnerability identified as CVE-2005-2056 represents a critical denial of service flaw within Clam AntiVirus version 0.86.1 and earlier releases. This issue specifically targets the Quantum archive decompressor component, which is responsible for handling compressed archive files during antivirus scanning operations. The vulnerability arises from insufficient input validation and error handling within the decompression logic, creating an exploitable condition that can be triggered remotely by malicious actors.
The technical flaw manifests when ClamAV processes a specially crafted Quantum archive file that contains malformed or maliciously constructed data structures. The Quantum archive format, used for storing compressed data, contains specific headers and metadata that the decompressor expects to follow predetermined patterns. When these patterns are violated through crafted input, the decompressor fails to properly handle the unexpected data, leading to memory corruption and subsequent application crash. This behavior aligns with CWE-121, which describes heap-based buffer overflow conditions, and CWE-122, which covers buffer overflow vulnerabilities in heap-based memory structures.
The operational impact of this vulnerability extends beyond simple service disruption, as it can be exploited remotely without requiring authentication or privileged access. Attackers can craft malicious Quantum archive files and deliver them through various vectors including email attachments, web downloads, or file sharing systems. When ClamAV attempts to scan these malicious archives during routine operations, the application crashes and terminates, effectively rendering the antivirus service unavailable for legitimate scanning tasks. This creates a denial of service condition that can be particularly damaging in enterprise environments where ClamAV serves as a critical security component for malware detection and prevention.
The vulnerability demonstrates a classic example of insufficient error handling in security software, where the decompressor lacks proper bounds checking and input validation mechanisms. According to ATT&CK framework category T1499, this vulnerability falls under the "Endpoint Denial of Service" technique, as it specifically targets endpoint security software to disrupt its normal operations. The flaw represents a failure in the principle of least privilege and defensive programming, as the decompressor should gracefully handle malformed input rather than crashing the entire application. Organizations using vulnerable versions of ClamAV face significant risk of service disruption, potential data loss, and compromised security posture during attack scenarios.
Mitigation strategies for CVE-2005-2056 require immediate deployment of ClamAV version 0.86.1 or later, which includes proper input validation and error handling for Quantum archive decompression. System administrators should also implement network-based filtering to block suspicious archive files and consider implementing additional monitoring for application crash events. The fix addresses the core issue by introducing proper bounds checking and memory management practices within the decompressor component, preventing the buffer overflow conditions that previously caused application instability. Security teams should also review their incident response procedures to ensure proper handling of denial of service events targeting security software components.