CVE-2002-2404 in IISPop
Summary
by MITRE
Buffer overflow in IISPop email server 1.161 and 1.181 allows remote attackers to cause a denial of service (crash) via a long request to the POP3 port (TCP port 110).
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Analysis
by VulDB Data Team • 08/26/2025
The vulnerability identified as CVE-2002-2404 represents a critical buffer overflow flaw within the IISPop email server versions 1.161 and 1.181. This security weakness specifically affects the POP3 service implementation that operates on TCP port 110, which is the standard port for POP3 email protocol communication. The flaw occurs when the server receives a malformed request containing an excessive amount of data that exceeds the allocated buffer space, leading to memory corruption and subsequent system instability.
The technical nature of this vulnerability aligns with CWE-121, which describes heap-based buffer overflow conditions where insufficient bounds checking allows attackers to write beyond allocated memory boundaries. The IISPop server fails to properly validate the length of incoming data from POP3 clients, particularly during authentication or command processing phases. When a remote attacker sends a specially crafted request containing more data than the server can handle, the excess data overflows into adjacent memory regions, potentially corrupting critical program state information and causing the application to crash or behave unpredictably.
From an operational perspective, this vulnerability presents a significant denial of service risk to organizations relying on IISPop email services. The impact extends beyond simple service disruption as the crash can potentially lead to complete system unavailability, affecting email communication for users within the affected organization. The remote nature of the attack means that adversaries can exploit this weakness from anywhere on the network without requiring local access or authentication credentials, making it particularly dangerous for systems exposed to the internet. Security professionals should note that this vulnerability was discovered during the early 2000s period when many organizations were still migrating to more robust email infrastructure, highlighting the importance of proper input validation in network services.
The mitigation strategies for CVE-2002-2404 should focus on immediate remediation through vendor-provided patches or updates to the IISPop server software. Organizations should also implement network segmentation and access controls to limit exposure of the affected POP3 port to trusted networks only. Network monitoring solutions should be configured to detect unusual traffic patterns or large data transfers to the TCP 110 port, which could indicate exploitation attempts. Additionally, implementing proper firewall rules to restrict access to the POP3 port from untrusted sources and considering the deployment of more modern email protocols such as IMAP4 or SMTP with proper authentication mechanisms would significantly reduce the attack surface and provide better overall security posture. The vulnerability demonstrates the critical importance of input validation and proper memory management in network services, principles that remain central to modern cybersecurity practices and align with ATT&CK technique T1499 for network denial of service attacks.