CVE-2004-2194 in Professional Edition
Summary
by MITRE
MailEnable Professional Edition before 1.53 and Enterprise Edition before 1.02 allows remote attackers to cause a denial of service (crash) via malformed (1) SMTP or (2) IMAP commands.
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Analysis
by VulDB Data Team • 07/09/2019
The vulnerability identified as CVE-2004-2194 affects MailEnable Professional Edition versions prior to 1.53 and Enterprise Edition versions prior to 1.02, representing a critical security flaw that enables remote attackers to execute denial of service attacks against mail servers. This vulnerability specifically targets the SMTP and IMAP protocol implementations within the MailEnable software, exploiting weaknesses in command parsing mechanisms that fail to properly handle malformed input sequences. The flaw resides in the server's inability to gracefully process malformed commands, leading to unexpected crashes and service disruptions that can severely impact email communication infrastructure.
The technical nature of this vulnerability falls under CWE-129, which addresses improper validation of input boundaries, and more specifically relates to CWE-20, which encompasses improper input validation in software systems. When remote attackers send carefully crafted malformed SMTP or IMAP commands to the vulnerable MailEnable servers, the software's parsing routines encounter unexpected data structures that trigger memory corruption or stack overflow conditions. These malformed commands exploit buffer handling weaknesses in the protocol processing code, causing the mail server processes to terminate abruptly and resulting in complete service unavailability for legitimate users.
From an operational perspective, this vulnerability presents a significant risk to organizations relying on MailEnable for their email infrastructure, as it can be exploited without requiring authentication or specialized knowledge of the target system. Attackers can simply connect to the mail server and send malicious commands to trigger the denial of service condition, making this vector particularly dangerous for public-facing email servers. The impact extends beyond simple service disruption to include potential business continuity issues, as email communication is often critical for organizational operations, and the vulnerability can be exploited at scale to target multiple servers simultaneously.
The mitigation strategies for this vulnerability involve immediate patching of the affected MailEnable versions to the recommended secure releases, specifically upgrading to MailEnable Professional Edition 1.53 or later and Enterprise Edition 1.02 or later. Organizations should also implement network-level protections such as firewall rules that restrict access to mail server ports from untrusted networks, and consider implementing intrusion detection systems that can identify and block malformed protocol commands. Additionally, administrators should monitor server logs for suspicious activity patterns and establish automated alerting mechanisms to detect potential exploitation attempts. The vulnerability demonstrates the importance of proper input validation and robust error handling in network services, aligning with ATT&CK technique T1499.004 for network denial of service attacks and highlighting the necessity of defensive coding practices that prevent malformed input from causing system instability.