CVE-2001-0679 in InterScan VirusWall
Summary
by MITRE
A buffer overflow in InterScan VirusWall 3.23 and 3.3 allows a remote attacker to execute arbitrary code by sending a long HELO command to the server.
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Analysis
by VulDB Data Team • 05/18/2025
The vulnerability identified as CVE-2001-0679 represents a critical buffer overflow flaw in InterScan VirusWall versions 3.23 and 3.3, a mail security appliance designed to protect email systems from malicious content. This vulnerability specifically affects the SMTP service component of the software, which is responsible for handling email transmission protocols. The flaw manifests when the system processes incoming SMTP HELO commands, which are standard protocol elements used by email servers to identify themselves during the initial connection phase of email communication.
The technical nature of this vulnerability stems from inadequate input validation within the InterScan VirusWall software implementation. When a remote attacker sends an excessively long HELO command to the vulnerable server, the application fails to properly bounds-check the input data before copying it into a fixed-size buffer allocated in memory. This classic buffer overflow condition occurs because the software does not verify that the length of the incoming command data remains within predefined limits, allowing the attacker to overwrite adjacent memory locations with malicious data. The overflow can potentially overwrite critical program variables, return addresses, or function pointers, providing an attacker with the means to redirect program execution flow.
The operational impact of this vulnerability is severe and far-reaching for organizations relying on InterScan VirusWall for email security. A successful exploitation could allow remote attackers to execute arbitrary code with the privileges of the affected service account, typically running with elevated system permissions. This compromise could lead to complete system takeover, data exfiltration, or the installation of persistent backdoors. The vulnerability affects the core email security infrastructure, potentially allowing attackers to bypass email filtering mechanisms and gain unauthorized access to the network. Organizations using this software would face significant risk of email-based attacks, as the vulnerability could be exploited without requiring authentication or prior access to the system.
Mitigation strategies for this vulnerability should focus on immediate patch deployment and network segmentation measures. The primary solution involves applying the official security patches released by the vendor to update the InterScan VirusWall software to versions that properly implement input validation and bounds checking. Organizations should also implement network-based controls such as firewalls and intrusion detection systems to monitor and filter SMTP traffic, particularly blocking or limiting HELO command lengths. Additionally, implementing proper access controls and network segmentation can limit the potential impact of successful exploitation. From a cybersecurity framework perspective, this vulnerability aligns with CWE-121, which describes stack-based buffer overflow conditions, and maps to ATT&CK technique T1203, which covers Exploitation for Client Execution. The vulnerability demonstrates the critical importance of input validation in network security appliances and highlights the necessity of regular security updates and vulnerability management processes. Organizations should also consider implementing application-level protections such as stack canaries or address space layout randomization to provide additional defense-in-depth measures against similar buffer overflow exploits.