CVE-2004-1546 in MDaemon
Summary
by MITRE
Multiple buffer overflows in MDaemon 6.5.1 allow remote attackers to cause a denial of service (application crash) via a long (1) SAML, SOML, SEND, or MAIL command to the SMTP server or (2) LIST command to the IMAP server.
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Analysis
by VulDB Data Team • 08/21/2025
The vulnerability identified as CVE-2004-1546 represents a critical security flaw in MDaemon email server software version 6.5.1 that exposes multiple buffer overflow conditions within the application's handling of specific SMTP and IMAP commands. This vulnerability falls under the CWE-121 buffer overflow category, where insufficient bounds checking allows malicious input to overwrite adjacent memory regions, potentially leading to application instability or complete system compromise. The affected commands include SAML, SOML, SEND, MAIL for SMTP server operations and LIST for IMAP server functions, indicating that the flaw exists in core email protocol handling mechanisms that process user input directly without adequate validation.
The operational impact of this vulnerability extends beyond simple denial of service conditions, as buffer overflows in network services can provide attackers with opportunities for more sophisticated exploitation techniques. When remote attackers craft specially formatted commands containing excessive input data, the MDaemon server processes these malformed inputs without proper boundary checks, causing memory corruption that results in application crashes and service disruption. This type of vulnerability aligns with ATT&CK technique T1499.004 which involves network denial of service attacks targeting email services, making it particularly dangerous in enterprise environments where email availability is critical for business operations. The vulnerability affects both SMTP and IMAP protocols, indicating a fundamental flaw in the server's input processing architecture rather than isolated command handling.
The technical nature of this flaw demonstrates poor input validation practices within the MDaemon email server implementation, where command arguments are not properly sanitized or length-limited before being processed by internal buffers. Attackers can exploit this by sending malformed commands that exceed the allocated buffer space, causing stack or heap corruption that leads to application termination. This vulnerability type is particularly concerning because email servers typically run with elevated privileges and are often exposed to the internet, making them attractive targets for exploitation. The fact that multiple command types are affected suggests that the underlying buffer management code lacks consistent input validation mechanisms, creating a systemic weakness rather than isolated command-specific flaws. Organizations relying on MDaemon 6.5.1 should immediately implement network segmentation and access controls to limit exposure while planning for software updates or patches to address this critical security weakness.
Mitigation strategies for this vulnerability should include immediate implementation of network access controls to restrict SMTP and IMAP server access to trusted sources only, along with monitoring for unusual command patterns that might indicate exploitation attempts. System administrators should consider deploying intrusion detection systems that can identify malformed email protocol commands, and implementing rate limiting to prevent rapid exploitation attempts. The most effective long-term solution involves upgrading to MDaemon versions that have addressed these buffer overflow conditions through proper input validation and bounds checking mechanisms. Organizations should also conduct comprehensive security assessments of their email infrastructure to identify similar vulnerabilities in other server applications and ensure that all network services implement robust input validation practices as recommended by industry standards including OWASP Top Ten and NIST guidelines for secure coding practices.