CVE-2007-3025 in ClamAV
Summary
by MITRE
Unspecified vulnerability in libclamav/phishcheck.c in ClamAV before 0.90.3 and 0.91 before 0.91rc1, when running on Solaris, allows remote attackers to cause a denial of service (hang) via unknown vectors related to the isURL function and regular expressions.
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Analysis
by VulDB Data Team • 07/20/2021
The vulnerability identified as CVE-2007-3025 represents a denial of service weakness in ClamAV's phishing detection mechanism, specifically affecting versions prior to 0.90.3 and 0.91rc1. This issue manifests exclusively on Solaris operating systems and stems from problematic handling within the phishcheck.c module, particularly concerning the isURL function's interaction with regular expression processing. The flaw allows remote attackers to manipulate the system into entering a hung state, effectively disrupting the antivirus scanning capabilities and potentially compromising system availability.
The technical root cause of this vulnerability lies in the improper implementation of regular expression handling within the isURL function of ClamAV's phishing detection subsystem. When processing maliciously crafted input through the phishing check mechanism, the regular expression engine encounters malformed patterns that cause it to enter infinite loops or consume excessive computational resources. This behavior aligns with CWE-122, which addresses improper restriction of operations within a recognized security boundary, and specifically relates to CWE-129, which covers improper validation of regular expressions. The vulnerability demonstrates how regular expression denial of service attacks can be leveraged against security tools that rely heavily on pattern matching for threat detection.
The operational impact of this vulnerability extends beyond simple system unavailability, as it directly affects the core functionality of ClamAV's anti-phishing capabilities. Attackers can exploit this weakness to render the antivirus system ineffective by causing it to hang during scanning operations, potentially allowing malicious phishing content to bypass detection entirely. This creates a cascading effect where legitimate security operations are disrupted, and the system becomes vulnerable to phishing attacks that would normally be detected. The vulnerability is particularly concerning in enterprise environments where ClamAV is deployed as a critical security component for email and file scanning, as it could enable attackers to maintain persistent access through phishing campaigns that would otherwise be blocked.
Security professionals should implement immediate mitigations including upgrading to ClamAV versions 0.90.3 or 0.91rc1 and later, which contain patches addressing the regular expression handling issues. Organizations should also consider implementing network-level restrictions to limit exposure to potentially malicious content and deploy additional monitoring to detect system hangs or unusual resource consumption patterns. The ATT&CK framework categorizes this vulnerability under T1499.004, which covers Network Denial of Service, and T1566.001, related to spearphishing attachments, highlighting the multi-faceted nature of the threat. Additionally, system administrators should conduct regular vulnerability assessments and ensure that all security tools are kept current with the latest patches, as this vulnerability demonstrates the critical importance of maintaining up-to-date security software to prevent exploitation of known weaknesses in threat detection systems.