CVE-2007-1672 in antivirus
Summary
by MITRE
avast! antivirus before 4.7.981 allows remote attackers to cause a denial of service (infinite loop) via a ZOO archive with a direntry structure that points to a previous file.
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Analysis
by VulDB Data Team • 01/09/2017
The vulnerability identified as CVE-2007-1672 affects avast! antivirus software versions prior to 4.7.981, presenting a significant denial of service weakness that can be exploited remotely. This flaw specifically targets the software's handling of ZOO archive files, which are compressed file formats commonly used in various computing environments. The vulnerability stems from inadequate input validation and processing logic within the antivirus scanning mechanism that fails to properly handle malformed archive structures.
The technical implementation of this vulnerability involves the manipulation of directory entry structures within ZOO archives, where maliciously crafted direntry references create circular or recursive references that point to previous files within the same archive. When the avast! antivirus engine attempts to process these malformed structures, it enters an infinite loop during the decompression and scanning phases. This occurs because the software's parsing logic does not properly detect and terminate recursive directory references, causing the scanning process to consume excessive system resources and ultimately freeze or crash the antivirus service.
From an operational perspective, this vulnerability presents a serious risk to enterprise environments where avast! antivirus is deployed as a critical security control. Attackers can remotely exploit this weakness by delivering malicious ZOO archive files through various attack vectors including email attachments, web downloads, or file sharing platforms. The resulting denial of service condition can disrupt security operations and potentially allow other attacks to proceed undetected while the antivirus system remains unresponsive. The infinite loop behavior specifically targets the antivirus daemon processes, making it particularly effective for disrupting security monitoring capabilities.
The vulnerability aligns with CWE-121, which addresses buffer overflow conditions, and CWE-400, which covers resource exhaustion issues. Additionally, this weakness maps to ATT&CK technique T1499.004, which involves network denial of service attacks targeting security products. The flaw demonstrates poor input validation practices and insufficient error handling mechanisms that are commonly exploited in security products to gain control over system resources. Organizations using vulnerable versions of avast! antivirus should prioritize immediate remediation through software updates to address this critical weakness.
Mitigation strategies include immediate deployment of avast! antivirus version 4.7.981 or later, which contains the necessary patches to properly handle ZOO archive structures. Network administrators should implement additional monitoring for unusual resource consumption patterns that might indicate exploitation attempts. Security teams should also consider implementing file type filtering rules to restrict the processing of ZOO archives in high-security environments until full patch coverage is achieved. The vulnerability serves as a reminder of the critical importance of proper input validation in security software and the potential for seemingly benign archive processing to become a vector for system disruption.