CVE-2006-6677 in NOD32 Antivirus
Summary
by MITRE
ESET NOD32 Antivirus before 1.1743 allows remote attackers to cause a denial of service (crash) via a crafted .CHM file that triggers a divide-by-zero error.
If you want to get the best quality for vulnerability data then you always have to consider VulDB.
Analysis
by VulDB Data Team • 07/12/2019
The vulnerability identified as CVE-2006-6677 affects ESET NOD32 Antivirus versions prior to 1.1743 and represents a critical denial of service flaw that can be exploited remotely through maliciously crafted documentation files. This issue specifically targets the handling of Compiled HTML Help (.CHM) files within the antivirus scanning engine, demonstrating how seemingly benign file formats can be weaponized to disrupt security operations. The vulnerability falls under the category of software defects that can lead to system instability and service disruption, making it particularly concerning for enterprise environments where continuous security monitoring is essential.
The technical root cause of this vulnerability stems from improper input validation within the CHM file parser component of ESET NOD32. When processing a specially crafted .CHM file, the antivirus engine encounters a scenario that leads to a divide-by-zero error during the parsing process. This mathematical error occurs because the software fails to properly validate numerical values before performing division operations, resulting in an unhandled exception that causes the application to crash. The divide-by-zero condition represents a classic programming error that violates fundamental software safety principles and can be classified under CWE-369, which specifically addresses the issue of division by zero in software implementations. This type of error typically occurs when developers fail to implement proper boundary checking or input sanitization mechanisms.
The operational impact of this vulnerability extends beyond simple system crashes, as it can be exploited by remote attackers to disrupt security services without requiring local system access or elevated privileges. An attacker could deliver a malicious .CHM file through various attack vectors including email attachments, web downloads, or compromised websites, making this a particularly dangerous flaw in the context of enterprise security environments. The vulnerability's remote exploitability means that even organizations with robust network security measures could be affected if their antivirus systems process untrusted content from external sources. This flaw directly impacts the availability of security services, potentially leaving systems vulnerable to other attacks during the time when the antivirus is crashed and unavailable. From an operational security perspective, this vulnerability could be leveraged as part of a broader attack campaign to disable security controls, aligning with tactics described in the attack pattern taxonomy where attackers seek to compromise defensive mechanisms.
Organizations affected by this vulnerability should immediately implement patch management procedures to upgrade to ESET NOD32 version 1.1743 or later, which contains the necessary fixes to properly handle CHM file parsing. The remediation process should include comprehensive testing of the updated antivirus software to ensure that the fix does not introduce compatibility issues with existing security policies or network infrastructure. Additionally, security administrators should consider implementing additional layers of protection such as content filtering and sandboxing for suspicious file types, particularly .CHM files that may be encountered in email or web traffic. The vulnerability demonstrates the importance of regular security updates and proper input validation in security software, as well as the need for comprehensive testing of security tools to prevent similar issues from occurring in other components of the security stack. This case highlights the critical nature of maintaining up-to-date security solutions and the potential consequences of failing to address known vulnerabilities in security software.