CVE-2002-1057 in Mailmax
Summary
by MITRE
Buffer overflow in SmartMax MailMax POP3 daemon (popmax) 4.8 allows remote attackers to execute arbitrary code via a long USER command.
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Analysis
by VulDB Data Team • 09/10/2025
The vulnerability described in CVE-2002-1057 represents a critical buffer overflow flaw within the SmartMax MailMax POP3 daemon version 4.8. This issue affects the popmax service that handles incoming email connections through the Post Office Protocol version 3 interface, which is a fundamental component of email server infrastructure. The vulnerability specifically manifests when the daemon processes a USER command that exceeds the allocated buffer space, creating an exploitable condition that can be leveraged by remote attackers to gain unauthorized system access. The flaw resides in the protocol implementation where insufficient input validation occurs before copying user-provided data into fixed-size memory buffers, a classic software security weakness that has been documented in numerous security advisories over the years.
The technical exploitation of this buffer overflow vulnerability occurs when a remote attacker sends a maliciously crafted USER command containing more data than the buffer can accommodate. When the popmax daemon processes this command, the excessive data overflows into adjacent memory regions, potentially overwriting critical program execution data such as return addresses or function pointers. This memory corruption enables attackers to redirect program execution flow and inject malicious code that executes with the privileges of the affected service. The vulnerability is particularly dangerous because it operates at the network level, allowing remote code execution without requiring authentication or local access to the system. According to CWE standards, this represents a CWE-121: Stack-based Buffer Overflow, which is categorized as a direct injection attack vector that can lead to complete system compromise.
The operational impact of this vulnerability extends beyond simple remote code execution to encompass full system compromise and potential data breaches. Organizations running affected versions of SmartMax MailMax POP3 daemon face significant risk of unauthorized access to email servers, which could result in email interception, data theft, or use as a foothold for further network infiltration. The vulnerability affects the core email infrastructure, potentially disrupting legitimate email services while simultaneously providing attackers with persistent access to the compromised system. From an attacker perspective, this vulnerability aligns with ATT&CK technique T1190: Exploit Public-Facing Application, where adversaries target network services to gain initial access to target systems. The attack chain typically involves reconnaissance to identify vulnerable systems followed by exploitation using the buffer overflow to establish a foothold for more extensive operations.
Mitigation strategies for this vulnerability require immediate action to address the root cause through proper input validation and memory management practices. Organizations should upgrade to patched versions of the SmartMax MailMax POP3 daemon or implement network-level restrictions to limit access to the affected service. The recommended approach includes applying vendor security patches as soon as they become available, implementing proper input length validation for all user commands, and configuring network firewalls to restrict access to POP3 ports from trusted networks only. Additionally, system administrators should consider implementing intrusion detection systems to monitor for suspicious USER command patterns and deploy application-level firewalls to filter potentially malicious inputs. The vulnerability also highlights the importance of regular security assessments and vulnerability scanning to identify similar buffer overflow conditions in other network services. Organizations should also implement principle of least privilege for email services and consider decommissioning older versions of mail servers that are no longer supported by vendors, as these legacy systems often contain unpatched security vulnerabilities that pose significant risk to overall network security posture.