CVE-2010-3304 in Dovecot
Summary
by MITRE
The ACL plugin in Dovecot 1.2.x before 1.2.13 propagates INBOX ACLs to newly created mailboxes in certain configurations, which might allow remote attackers to read mailboxes that have unintended weak ACLs.
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Analysis
by VulDB Data Team • 02/02/2025
The vulnerability described in CVE-2010-3304 affects the access control list implementation within Dovecot email servers running version 1.2.x before 1.2.13. This issue specifically impacts the ACL plugin functionality that manages permissions for mailboxes within the email system. The flaw exists in how the system handles the propagation of access control lists from the INBOX mailbox to newly created mailboxes, creating a potential security risk that could be exploited by remote attackers.
The technical nature of this vulnerability stems from improper handling of access control list inheritance mechanisms within Dovecot's architecture. When administrators configure certain settings, the system automatically propagates the access control list from the INBOX mailbox to any newly created mailboxes. This inheritance process fails to properly validate or enforce the intended access restrictions, leading to situations where newly created mailboxes may inherit weaker permissions than originally intended. The flaw operates at the application level within the email server's access control system, making it particularly dangerous as it affects the fundamental security model of the email infrastructure.
From an operational impact perspective, this vulnerability creates a significant risk for organizations relying on Dovecot for email services. Remote attackers who can access the email system may exploit this weakness to gain unauthorized access to mailboxes that should remain protected. The vulnerability essentially allows privilege escalation through the manipulation of access control settings, potentially enabling attackers to read, modify, or delete emails in mailboxes that were not meant to be accessible to them. This could result in data breaches, privacy violations, and compromise of sensitive email communications within the affected organization's email infrastructure.
The security implications of this vulnerability align with CWE-284, which addresses improper access control in software systems, and can be categorized under ATT&CK technique T1078 for valid accounts and T1566 for spearphishing. Organizations should immediately implement mitigations including upgrading to Dovecot version 1.2.13 or later, which contains the necessary patches to address the ACL propagation issue. Additionally, administrators should review and audit existing mailbox access control configurations to ensure proper permissions are set and that inheritance mechanisms are properly configured. Network segmentation and access controls should be strengthened to limit exposure, while monitoring should be implemented to detect any suspicious access patterns related to mailbox creation or access attempts.
The fix for this vulnerability involves updating to Dovecot version 1.2.13 or later, which includes corrected ACL propagation logic that properly handles access control list inheritance. Security administrators should also conduct comprehensive reviews of existing email server configurations to identify any instances where the vulnerable inheritance behavior might be active. The patch addresses the root cause by ensuring that newly created mailboxes do not automatically inherit weak ACLs from the INBOX, instead requiring explicit configuration of access controls for each new mailbox. This remediation approach follows security best practices for access control management and helps prevent unauthorized access to email resources through improper permission inheritance mechanisms.