CVE-2000-0507 in IMate Webmail Server
Summary
by MITRE
Imate Webmail Server 2.5 allows remote attackers to cause a denial of service via a long HELO command.
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Analysis
by VulDB Data Team • 04/23/2025
The CVE-2000-0507 vulnerability affects the Imate Webmail Server version 2.5, representing a classic buffer overflow condition that manifests through improper handling of the SMTP HELO command. This vulnerability resides within the server's mail handling functionality where the application fails to properly validate input length during the initial SMTP handshake process. When a remote attacker sends an excessively long HELO command to the server, the application's buffer management mechanisms cannot accommodate the oversized input, leading to memory corruption and subsequent service disruption.
The technical flaw stems from inadequate input validation and boundary checking within the SMTP protocol implementation. The HELO command serves as the initial greeting in the SMTP communication process, where clients identify themselves to the mail server. In this case, the Imate Webmail Server 2.5 processes the HELO argument without implementing proper length restrictions or input sanitization, creating a condition where attacker-controlled data can overflow the allocated buffer space. This type of vulnerability aligns with CWE-121, which describes stack-based buffer overflow conditions, and represents a fundamental security weakness in input processing mechanisms. The vulnerability operates at the network protocol level, specifically targeting the Simple Mail Transfer Protocol implementation within the webmail server's mail subsystem.
The operational impact of this vulnerability extends beyond simple service disruption to potentially compromise the entire mail server infrastructure. When exploited, the denial of service condition can render the mail server completely inaccessible to legitimate users, effectively blocking email communication for all users of the affected system. Attackers can leverage this vulnerability to perform persistent DoS attacks that may require manual intervention to resolve, including server restarts or application reinstallation. The attack vector is particularly concerning as it requires no authentication or specialized privileges, making it accessible to any remote attacker with network connectivity to the server. This vulnerability can be classified under the MITRE ATT&CK technique T1499.004, which covers network denial of service attacks, and represents a critical weakness in the server's resilience against malformed input processing.
Mitigation strategies for CVE-2000-0507 should focus on implementing immediate input validation measures and applying available security patches from the vendor. Organizations should configure the mail server to enforce strict limits on HELO command length, typically restricting input to standard SMTP protocol limits of 255 characters. Network-level protections can include implementing firewall rules that monitor and limit SMTP traffic patterns, as well as deploying intrusion detection systems that can identify and block suspicious HELO command sequences. The most effective long-term solution involves upgrading to a patched version of the Imate Webmail Server or migrating to a more secure mail server implementation that properly handles input validation. Security administrators should also implement regular vulnerability assessments and penetration testing to identify similar buffer overflow conditions in other network services and applications, as this vulnerability type remains prevalent in legacy systems and can be exploited across various protocols and implementations.