CVE-2001-0584 in MDaemon
Summary
by MITRE
IMAP server in Alt-N Technologies MDaemon 3.5.6 allows a local user to cause a denial of service (hang) via long (1) SELECT or (2) EXAMINE commands.
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Analysis
by VulDB Data Team • 10/05/2025
The vulnerability identified as CVE-2001-0584 affects the IMAP server component of Alt-N Technologies MDaemon version 3.5.6, representing a significant security flaw that enables local users to trigger denial of service conditions. This issue specifically targets the IMAP protocol implementation within the MDaemon email server software, which serves as a critical communication infrastructure for many organizations. The vulnerability manifests when a local attacker submits excessively long SELECT or EXAMINE commands to the IMAP server, causing the service to become unresponsive and effectively hang. The impact extends beyond simple service interruption as it can render email services unavailable to legitimate users, potentially disrupting business operations and communication channels that depend on the affected MDaemon installation.
The technical root cause of this vulnerability lies in the insufficient input validation and boundary checking mechanisms implemented within the IMAP server's command processing logic. When the server receives a SELECT or EXAMINE command with an abnormally long argument string, the parsing and processing functions fail to properly handle the excessive input length, leading to resource exhaustion or infinite loop conditions. This flaw represents a classic buffer overflow or input length validation issue that falls under CWE-122, which describes insufficient input length validation. The vulnerability operates at the application layer of the network stack and specifically targets the IMAP protocol implementation where the server processes mailbox selection commands. The local user privilege requirement indicates that an attacker must already have access to the system to exploit this vulnerability, though this access level significantly reduces the attack complexity compared to remote exploitation scenarios.
From an operational impact perspective, this vulnerability creates substantial risk for organizations relying on MDaemon email services, as it can result in complete service disruption for email communication. The denial of service condition causes the IMAP server to become unresponsive, preventing legitimate users from accessing their email accounts, checking mailboxes, or performing standard email operations. This disruption can cascade through business processes that depend on email communication, affecting customer service, internal communications, and administrative functions. The vulnerability's local user requirement means that it can be exploited by any user with system access, including potentially compromised accounts or insider threats, making it particularly concerning for organizations with less stringent access controls. Security professionals should note that while the vulnerability requires local access, it can be particularly dangerous in environments where multiple users have system privileges or where privilege escalation techniques might be employed to gain the necessary access level.
The mitigation strategies for CVE-2001-0584 primarily focus on implementing proper input validation and boundary checking mechanisms within the IMAP server implementation. Organizations should immediately apply patches or updates provided by Alt-N Technologies to address this vulnerability, as the vendor would have released a fix that includes enhanced input length validation for SELECT and EXAMINE commands. System administrators should also consider implementing monitoring solutions that can detect anomalous command patterns or unusually long input sequences that might indicate exploitation attempts. Network segmentation and access control measures can help limit the potential impact by restricting local user access to the MDaemon service where possible. Additionally, implementing proper logging and alerting mechanisms around IMAP server activity can help security teams detect and respond to exploitation attempts before they cause significant service disruption. This vulnerability aligns with ATT&CK technique T1499 which covers network denial of service attacks, and the remediation approach should include both preventive measures through proper input validation and detective controls through monitoring and logging. Organizations should also consider implementing application-level firewalls or intrusion prevention systems that can detect and block malformed IMAP commands before they reach the vulnerable server components.