CVE-2010-0098 in ClamAV
Summary
by MITRE
ClamAV before 0.96 does not properly handle the (1) CAB and (2) 7z file formats, which allows remote attackers to bypass virus detection via a crafted archive that is compatible with standard archive utilities.
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Analysis
by VulDB Data Team • 09/07/2021
The vulnerability identified as CVE-2010-0098 affects ClamAV versions prior to 0.96 and represents a significant bypass of antivirus detection mechanisms through improper handling of archive file formats. This flaw specifically impacts the processing of CAB and 7z compressed archives, which are commonly used across various operating systems and applications. The vulnerability stems from the inability of the antivirus engine to correctly parse and analyze these archive formats, creating opportunities for malicious payloads to evade detection.
The technical implementation of this vulnerability occurs at the archive parsing layer within ClamAV's detection engine. When processing CAB and 7z files, the software fails to properly validate or decompress the archive contents, allowing attackers to craft malicious archives that appear legitimate to standard archive utilities while containing hidden malicious code. This parsing failure creates a gap in the antivirus's ability to perform thorough content inspection, effectively enabling the bypass of security controls that should detect malicious activity within compressed files. The flaw represents a classic case of incomplete input validation and improper error handling in archive processing components.
The operational impact of this vulnerability extends beyond simple detection bypass, as it allows attackers to deliver malware through seemingly benign archive files that are compatible with standard system utilities. This creates a significant risk for organizations relying on ClamAV for endpoint protection, as the vulnerability can be exploited through various attack vectors including email attachments, web downloads, and removable media. The ability to craft archives that evade detection while remaining functional with standard utilities makes this vulnerability particularly dangerous in enterprise environments where users frequently interact with compressed files from external sources.
This vulnerability aligns with CWE-20, "Improper Input Validation," and CWE-129, "Improper Validation of Array Index," as it demonstrates inadequate validation of archive file structures and content parsing. From an ATT&CK framework perspective, this vulnerability maps to TA0005 "Defense Evasion" and TA0002 "Execution" where adversaries can bypass security controls and execute malicious code. The attack surface is particularly relevant in environments where users have elevated privileges or where automated scanning systems rely on ClamAV for threat detection. Organizations using older versions of ClamAV should consider immediate remediation to address this vulnerability.
Mitigation strategies should include immediate upgrade to ClamAV version 0.96 or later, which contains the necessary fixes for proper archive format handling. Additionally, organizations should implement layered security approaches including network-based scanning, application whitelisting, and user education about suspicious file attachments. Regular security assessments should verify that updated antivirus signatures are properly deployed and that archive processing configurations are correctly implemented. The vulnerability serves as a reminder of the importance of maintaining up-to-date security software and the critical need for proper input validation in security applications to prevent exploitation of parsing vulnerabilities that can undermine entire defense infrastructures.