CVE-2010-3780 in Dovecot
Summary
by MITRE
Dovecot 1.2.x before 1.2.15 allows remote authenticated users to cause a denial of service (master process outage) by simultaneously disconnecting many (1) IMAP or (2) POP3 sessions.
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Analysis
by VulDB Data Team • 09/26/2021
The vulnerability identified as CVE-2010-3780 represents a significant denial of service weakness in Dovecot email servers running versions 1.2.x prior to 1.2.15. This flaw specifically affects the master process that manages IMAP and POP3 services, creating a critical operational risk for email infrastructure. The vulnerability stems from inadequate session handling mechanisms that fail to properly manage concurrent disconnections, leading to system instability and complete service interruption.
The technical exploitation of this vulnerability involves authenticated users leveraging their legitimate access rights to simultaneously terminate multiple IMAP or POP3 sessions in a coordinated manner. When these disconnections occur concurrently, the master process becomes overwhelmed by the rapid succession of session termination events, causing it to crash or become unresponsive. This behavior demonstrates a classic resource exhaustion pattern where the system's ability to handle concurrent operations is exceeded, resulting in process failure rather than graceful degradation.
From an operational impact perspective, this vulnerability presents a severe threat to email service availability and reliability. Organizations relying on Dovecot for their email infrastructure face potential service outages that could affect thousands of users simultaneously. The authentication requirement limits the attack surface to legitimate users, but this also means that compromised accounts or insider threats could exploit this weakness. The master process outage directly impacts both IMAP and POP3 services, potentially affecting email retrieval, sending capabilities, and overall system responsiveness.
This vulnerability aligns with CWE-400, which categorizes resource exhaustion flaws in software systems, and demonstrates characteristics consistent with attack patterns documented in the MITRE ATT&CK framework under the denial of service tactic. The weakness specifically relates to process management and resource handling within the mail server architecture, where proper session lifecycle management fails to account for concurrent disconnection scenarios. Organizations should implement immediate patching strategies to address this vulnerability, as well as monitor for unusual session disconnection patterns that might indicate exploitation attempts. The fix included in Dovecot 1.2.15 properly handles concurrent session termination events through improved process synchronization and resource management mechanisms, preventing the master process from becoming overwhelmed during high-volume disconnection scenarios.