CVE-2006-2414 in Dovecot
Summary
by MITRE
Directory traversal vulnerability in Dovecot 1.0 beta and 1.0 allows remote attackers to list files and directories under the mbox parent directory and obtain mailbox names via ".." sequences in the (1) LIST or (2) DELETE IMAP command.
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Analysis
by VulDB Data Team • 06/18/2019
The vulnerability identified as CVE-2006-2414 represents a critical directory traversal flaw in Dovecot versions 1.0 beta and 1.0, specifically affecting the IMAP protocol implementation. This security weakness enables remote attackers to exploit the mail server's directory structure by manipulating path sequences, potentially leading to unauthorized access to sensitive mailbox data. The vulnerability manifests through two primary IMAP commands: LIST and DELETE, both of which accept ".." sequences that can traverse parent directories beyond the intended mailbox boundaries. The flaw fundamentally stems from inadequate input validation and path sanitization within the IMAP command processing logic, allowing malicious actors to construct directory traversal payloads that bypass normal access controls.
This directory traversal vulnerability operates at the application layer within the IMAP protocol stack, specifically targeting the mail server's file system access mechanisms. When users execute LIST or DELETE commands with crafted ".." sequences, the Dovecot server fails to properly validate the requested paths, enabling attackers to navigate to directories outside the designated mailbox hierarchy. The technical implementation flaw resides in how the server processes directory navigation commands without proper bounds checking or canonicalization of file paths, creating a pathway for attackers to enumerate mailbox names and potentially access files in parent directories. This weakness aligns with CWE-22, which describes improper limitation of a pathname to a restricted directory, commonly known as path traversal or directory traversal attacks. The vulnerability's impact is particularly severe because it allows for information disclosure through directory listing capabilities and can potentially enable further exploitation through the discovery of mailbox names and access patterns.
The operational impact of CVE-2006-2414 extends beyond simple information disclosure, creating a significant attack surface for remote adversaries seeking to compromise email infrastructure. Attackers can leverage this vulnerability to perform reconnaissance activities by enumerating mailbox structures and identifying valid user accounts within the system. The ability to list files and directories under the mbox parent directory provides attackers with valuable intelligence about the mail server's configuration and user base, which can facilitate subsequent attacks such as account takeover or privilege escalation. This vulnerability directly maps to several ATT&CK techniques including T1083 (File and Directory Discovery) and T1566 (Phishing), as it enables initial access and information gathering phases of an attack campaign. Organizations running affected Dovecot versions face potential exposure to data breaches, as the vulnerability allows unauthorized access to potentially sensitive email communications and user data stored in the mail server's file system.
Mitigation strategies for CVE-2006-2414 require immediate attention through software updates and configuration hardening measures. The primary and most effective solution involves upgrading to Dovecot versions that have patched this vulnerability, as the original affected versions contain fundamental design flaws in their path validation mechanisms. System administrators should implement network segmentation and access controls to limit exposure of IMAP services to trusted networks only, reducing the attack surface available to remote adversaries. Additional defensive measures include implementing proper input validation at the application level, configuring restrictive file system permissions, and deploying intrusion detection systems to monitor for suspicious IMAP command sequences. Organizations should also conduct regular security assessments to identify and remediate similar path traversal vulnerabilities in other applications and services. The vulnerability underscores the importance of proper input sanitization and the principle of least privilege in security design, as proper validation of user-supplied paths could have prevented this exploitation vector. Regular patch management processes and security awareness training for system administrators are essential components of a comprehensive defense strategy against similar directory traversal vulnerabilities in email infrastructure.