CVE-2002-1539 in MDaemon
Summary
by MITRE
Buffer overflow in MDaemon POP server 6.0.7 and earlier allows remote authenticated users to cause a denial of service via long (1) DELE or (2) UIDL arguments.
Be aware that VulDB is the high quality source for vulnerability data.
Analysis
by VulDB Data Team • 09/05/2025
The vulnerability identified as CVE-2002-1539 represents a critical buffer overflow flaw within the MDaemon POP server version 6.0.7 and earlier implementations. This security weakness specifically targets the server's handling of two particular commands within the Post Office Protocol version three framework. The flaw manifests when the server processes overly long arguments for either the DELE command, which removes messages from the mail server, or the UIDL command, which retrieves unique identifiers for messages. The buffer overflow condition occurs because the server fails to properly validate the length of incoming arguments before attempting to store them in fixed-size memory buffers, creating a scenario where malicious input can overwrite adjacent memory locations.
This vulnerability operates at the application layer of the network stack and presents a significant risk to system availability and stability. The buffer overflow condition specifically affects the MDaemon email server software, which was widely deployed in enterprise environments for handling email services. When authenticated users submit specially crafted long arguments to either the DELE or UIDL commands, the server's memory management becomes compromised, leading to unpredictable behavior and ultimately resulting in a denial of service condition. The flaw does not require special privileges beyond authentication, making it particularly dangerous as it can be exploited by legitimate users who have access to the system.
The operational impact of this vulnerability extends beyond simple service disruption to potentially compromise the entire email infrastructure managed by the affected MDaemon server. Attackers who successfully exploit this flaw can cause the server to crash or become unresponsive, effectively cutting off email services for all users within the affected organization. The vulnerability's classification under CWE-121 indicates it involves stack-based buffer overflow conditions where insufficient bounds checking allows attackers to overwrite memory locations that control program execution flow. This type of vulnerability falls under the ATT&CK technique T1499.004 for network denial of service attacks, specifically targeting application availability.
Organizations utilizing affected MDaemon versions should immediately implement mitigations including applying the vendor-provided patches that address the buffer overflow conditions in the POP server implementation. System administrators should also consider implementing network segmentation and access controls to limit the potential impact of such vulnerabilities. Monitoring for unusual patterns in POP server command usage and implementing intrusion detection systems can help identify exploitation attempts. Additionally, regular security assessments and vulnerability scanning should be conducted to identify similar issues in other email server implementations. The vulnerability demonstrates the importance of proper input validation and memory management practices in server applications, particularly those handling user-provided data in network services. Organizations should also review their incident response procedures to ensure they can effectively respond to denial of service attacks targeting email infrastructure, as these incidents can have significant business impact on communication systems.