CVE-2004-2501 in Professional Edition
Summary
by MITRE
Buffer overflow in the IMAP service of MailEnable Professional Edition 1.52 and Enterprise Edition 1.01 allows remote attackers to execute arbitrary code via (1) a long command string or (2) a long string to the MEIMAP service and then terminating the connection.
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Analysis
by VulDB Data Team • 09/12/2025
The vulnerability described in CVE-2004-2501 represents a critical buffer overflow flaw within the IMAP service component of MailEnable email server software. This issue affects both MailEnable Professional Edition version 1.52 and Enterprise Edition version 1.01, making it a widespread concern for organizations relying on these email server implementations. The vulnerability stems from insufficient input validation and boundary checking within the IMAP service handling mechanism, specifically when processing command strings and connection termination sequences. The flaw manifests when the service receives malformed input that exceeds predetermined buffer limits, creating conditions where attacker-controlled data can overwrite adjacent memory locations.
The technical exploitation of this vulnerability occurs through two primary vectors that leverage different aspects of the IMAP protocol implementation. The first attack vector involves sending an excessively long command string to the MEIMAP service, while the second vector exploits the service's handling of connection termination sequences. Both approaches capitalize on the same underlying buffer overflow condition where insufficient bounds checking allows memory corruption to occur. When the service processes these malformed inputs, the overflow can overwrite critical program execution structures including return addresses, function pointers, or other control data that govern program flow. This memory corruption creates opportunities for attackers to inject and execute arbitrary code within the context of the IMAP service process, potentially leading to complete system compromise.
The operational impact of this vulnerability extends beyond simple code execution to encompass significant security implications for affected organizations. Successful exploitation can result in unauthorized access to email servers, enabling attackers to read, modify, or delete email messages stored on the server. The vulnerability also poses risks to network infrastructure as compromised servers can serve as launching points for further attacks against internal network resources. Additionally, the attack vectors are particularly concerning because they can be executed remotely without requiring authentication, making the vulnerability accessible to attackers anywhere on the internet. The nature of the IMAP service being a standard email protocol implementation means that organizations with mail servers exposing this service to external networks are at risk, regardless of their security posture.
Organizations affected by this vulnerability should implement immediate mitigations including applying the vendor-provided security patches and updates. Network segmentation strategies should be employed to limit access to the IMAP service to trusted internal networks only, while firewall rules can be configured to restrict external access to the specific ports used by the IMAP service. The vulnerability aligns with CWE-121, which describes stack-based buffer overflow conditions, and represents a classic example of how improper input validation can lead to arbitrary code execution. From an adversarial perspective, this vulnerability maps to ATT&CK technique T1075 which covers use of valid accounts for persistence, and T1059 which encompasses command and scripting interpreter usage. System administrators should also consider implementing intrusion detection systems capable of identifying suspicious IMAP traffic patterns and monitoring for indicators of compromise related to this specific vulnerability. Regular security assessments and vulnerability scanning should be conducted to identify any remaining instances of the vulnerable MailEnable versions within the organization's infrastructure.