CVE-2004-1011 in Cyrus IMAP Server
Summary
by MITRE
Stack-based buffer overflow in Cyrus IMAP Server 2.2.4 through 2.2.8, with the imapmagicplus option enabled, allows remote attackers to execute arbitrary code via a long (1) PROXY or (2) LOGIN command, a different vulnerability than CVE-2004-1015.
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Analysis
by VulDB Data Team • 06/05/2019
The vulnerability described in CVE-2004-1011 represents a critical stack-based buffer overflow affecting the Cyrus IMAP Server version 2.2.4 through 2.2.8 when the imapmagicplus option is enabled. This flaw exists within the server's handling of specific IMAP commands and presents a significant security risk to organizations relying on this email infrastructure component. The vulnerability specifically targets the PROXY and LOGIN command processing mechanisms, making it particularly dangerous as these commands are fundamental to IMAP protocol operations and user authentication processes.
The technical implementation of this buffer overflow stems from inadequate input validation within the Cyrus IMAP server's command parsing routines. When the imapmagicplus option is enabled, the server's stack memory management becomes susceptible to overflows during processing of specially crafted PROXY or LOGIN commands containing excessive data payloads. This occurs because the server fails to properly bounds-check the length of incoming command parameters before copying them into fixed-size stack buffers, allowing attackers to overwrite adjacent memory locations including return addresses and control data. The vulnerability is classified under CWE-121 as a stack-based buffer overflow, which directly enables arbitrary code execution through manipulation of the program's execution flow.
From an operational perspective, this vulnerability creates a severe attack surface for remote threat actors who can leverage the buffer overflow to execute arbitrary code on affected systems. The implications extend beyond simple code execution to potentially provide attackers with full system compromise capabilities, especially when considering that IMAP servers often operate with elevated privileges and access to sensitive email data. Attackers can exploit this vulnerability without authentication requirements for the PROXY command, while LOGIN command exploitation requires only valid credentials but can lead to privilege escalation within the server environment. The vulnerability's classification as a remote code execution flaw places it within the ATT&CK framework's T1203 (Exploitation for Client Execution) and T1059 (Command and Scripting Interpreter) tactics, demonstrating how attackers can leverage network-based protocols to gain unauthorized access.
Organizations affected by this vulnerability should implement immediate mitigations including disabling the imapmagicplus option when not strictly required, applying the vendor-provided security patches, and monitoring network traffic for exploitation attempts. Network segmentation and firewall rules should be configured to restrict access to IMAP services to trusted networks only, while implementing intrusion detection systems to monitor for suspicious PROXY and LOGIN command patterns. The vulnerability highlights the importance of input validation and proper memory management in server applications, particularly those handling network-based protocols where external input validation is critical. Security teams should also consider implementing automated patch management processes to ensure timely deployment of security updates and conduct regular vulnerability assessments to identify similar issues within other server applications. The remediation process should include thorough testing of patches in controlled environments to prevent service disruption while ensuring complete vulnerability resolution.