CVE-2001-1280 in IMail
Summary
by MITRE
POP3 Server for Ipswitch IMail 7.04 and earlier generates different responses to valid and invalid user names, which allows remote attackers to determine users on the system.
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Analysis
by VulDB Data Team • 09/27/2025
The vulnerability described in CVE-2001-1280 represents a classic account enumeration flaw that affects the POP3 server component of Ipswitch IMail versions 7.04 and earlier. This issue stems from the server's inconsistent response behavior when processing authentication requests from remote clients. The fundamental problem lies in how the server handles user validation attempts, specifically generating distinct response messages for legitimate versus non-existent user accounts during the POP3 authentication process.
This technical weakness creates a significant information disclosure risk that directly violates security principles outlined in the CWE (Common Weakness Enumeration) catalog under CWE-200, which addresses improper error handling and information exposure. The server's response differentiation allows attackers to systematically identify valid user accounts through brute force or dictionary attacks, effectively enabling account enumeration techniques that compromise the confidentiality and integrity of the email system. The vulnerability operates at the application layer and specifically targets the authentication mechanism of the POP3 protocol implementation within the IMail server software.
The operational impact of this vulnerability extends beyond simple user enumeration, as it provides attackers with a crucial foothold for subsequent attack phases. Once valid user accounts are identified, attackers can proceed with password guessing, credential stuffing, or more sophisticated social engineering campaigns targeting specific individuals within the organization. The vulnerability affects organizations that rely on IMail for email services and creates a persistent threat vector that remains exploitable as long as the vulnerable software remains in operation. According to ATT&CK framework categorization under T1078 (Valid Accounts) and T1566 (Phishing), this vulnerability enables initial access through account compromise and can facilitate further lateral movement within the network.
Mitigation strategies for CVE-2001-1280 focus primarily on software updates and configuration hardening. Organizations should immediately upgrade to Ipswitch IMail versions that address this vulnerability, as the manufacturer has provided patches to resolve the inconsistent response behavior. Additionally, implementing rate limiting and account lockout mechanisms can help reduce the effectiveness of automated enumeration attempts. Network-level protections such as firewall rules that limit POP3 access from untrusted networks and implementing intrusion detection systems that monitor for suspicious authentication patterns provide supplementary defense measures. The vulnerability demonstrates the critical importance of maintaining up-to-date software and proper security configuration management practices as outlined in various cybersecurity frameworks including NIST SP 800-53 and ISO 27001 standards for information security control implementation.