CVE-2014-2014 in imapsync
Summary
by MITRE
imapsync before 1.584, when running with the --tls option, attempts a cleartext login when a certificate verification failure occurs, which allows remote attackers to obtain credentials by sniffing the network.
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Analysis
by VulDB Data Team • 05/11/2026
The vulnerability described in CVE-2014-2014 affects imapsync versions prior to 1.584 and represents a critical security flaw in the handling of TLS certificate verification failures during email synchronization operations. This issue specifically manifests when the imapsync utility is executed with the --tls option, which is designed to establish secure encrypted connections to IMAP servers. The flaw creates a dangerous fallback mechanism that undermines the security assurances typically provided by Transport Layer Security protocols.
The technical implementation of this vulnerability stems from improper error handling within the TLS handshake process. When imapsync encounters a certificate verification failure, instead of terminating the connection attempt or alerting the user to the security issue, it automatically reverts to a cleartext login mechanism. This behavior violates fundamental security principles by allowing credential transmission over unencrypted channels when the expected secure connection cannot be established. The flaw essentially creates a backdoor where authentication credentials become exposed to network sniffing tools, making it trivial for attackers positioned within the network to capture sensitive information.
From an operational impact perspective, this vulnerability exposes organizations to significant risk during email synchronization activities. The attack vector requires minimal sophistication as network sniffing tools can capture the cleartext credentials without requiring complex exploitation techniques. This makes the vulnerability particularly dangerous in environments where network traffic is not properly secured or monitored, such as public Wi-Fi networks, corporate networks with insufficient segmentation, or when users connect from untrusted locations. The compromised credentials can then be used for unauthorized access to email accounts, potentially leading to data breaches, privilege escalation, and further network infiltration.
The vulnerability aligns with CWE-295 which addresses improper certificate validation, and demonstrates characteristics consistent with ATT&CK technique T1566 related to credential access through network sniffing. Organizations using imapsync in production environments face potential exposure to man-in-the-middle attacks where attackers can intercept and utilize the captured credentials for unauthorized access to email systems. The flaw represents a failure in secure coding practices where proper error handling should prevent fallback to insecure protocols rather than automatically switching to cleartext authentication.
Mitigation strategies should prioritize immediate patching of imapsync installations to version 1.584 or later, which contains the necessary fixes to prevent the automatic cleartext fallback behavior. Network administrators should also implement additional monitoring to detect unusual authentication patterns and ensure that all email synchronization processes enforce proper TLS certificate validation. Organizations should consider implementing network segmentation to limit the impact of credential interception and deploy intrusion detection systems capable of identifying suspicious network traffic patterns associated with credential capture attempts. Additionally, regular security assessments should verify that TLS configurations are properly enforced and that fallback mechanisms are appropriately controlled to prevent similar vulnerabilities in other network utilities and email clients.