CVE-2000-0033 in Interscan Viruswall
Summary
by MITRE
InterScan VirusWall SMTP scanner does not properly scan messages with malformed attachments.
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Analysis
by VulDB Data Team • 10/19/2025
The vulnerability identified as CVE-2000-0033 affects the InterScan VirusWall SMTP scanner, a security solution designed to protect email systems from malicious content. This flaw represents a critical weakness in the email filtering mechanism that processes incoming SMTP traffic. The vulnerability specifically targets the scanner's inability to properly analyze messages containing malformed attachments, which creates a potential bypass for malicious payloads that could otherwise be detected by standard antivirus scanning procedures. The issue stems from insufficient validation and parsing mechanisms within the scanner's attachment handling code, allowing crafted malformed attachments to evade detection.
The technical implementation of this vulnerability involves the scanner's failure to properly parse and validate attachment structures that deviate from standard formats. When an email contains an attachment with malformed headers, incorrect encoding, or other structural irregularities, the InterScan VirusWall system does not adequately process these elements through its signature-based or heuristic scanning mechanisms. This weakness can be exploited through carefully constructed email messages that contain malicious content embedded within malformed attachments, potentially allowing malware to bypass the security controls. The flaw operates at the application layer of the email security stack, specifically within the SMTP protocol processing component that handles message inspection and filtering.
From an operational impact perspective, this vulnerability creates significant risk for organizations relying on InterScan VirusWall for email security. Attackers could potentially deliver malicious payloads through email channels that would otherwise be blocked by the system's normal scanning processes. The vulnerability could enable the delivery of trojans, worms, or other malware that exploits the gap in the scanning mechanism. Organizations may experience unauthorized access to their networks, data breaches, or system compromises when attackers leverage this weakness to bypass email security controls. The impact extends beyond immediate security concerns to include potential regulatory compliance violations and business continuity issues.
The vulnerability aligns with CWE-129, which addresses improper validation of input boundaries, and demonstrates characteristics consistent with the ATT&CK technique T1190 for Exploit Public-Facing Application. Mitigation strategies should include immediate deployment of vendor patches or updates to address the malformed attachment handling issue. Organizations should also implement additional email security layers including content filtering, sandboxing, and multi-layered inspection techniques. Network segmentation and email monitoring should be enhanced to detect anomalous email traffic patterns that might indicate exploitation attempts. Regular security assessments and vulnerability scanning should be conducted to identify similar weaknesses in other email security solutions within the organization's infrastructure.