CVE-2014-7273 in getmail
Summary
by MITRE
The IMAP-over-SSL implementation in getmail 4.0.0 through 4.43.0 does not verify X.509 certificates from SSL servers, which allows man-in-the-middle attackers to spoof IMAP servers and obtain sensitive information via a crafted certificate.
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Analysis
by VulDB Data Team • 03/29/2022
The vulnerability described in CVE-2014-7273 represents a critical security flaw in the getmail email retrieval utility that affects versions 4.0.0 through 4.43.0. This issue specifically targets the IMAP-over-SSL implementation where the software fails to properly validate X.509 certificates presented by SSL servers during the secure connection establishment process. The absence of certificate verification creates a significant attack surface that enables malicious actors to perform man-in-the-middle attacks against email communications. This vulnerability directly impacts the integrity and confidentiality of email data transmission, as attackers can present forged certificates that appear legitimate to the vulnerable client software.
The technical root cause of this vulnerability stems from improper SSL/TLS certificate validation within the getmail application's IMAP implementation. When getmail establishes a secure connection to an IMAP server using SSL, it should verify that the server's certificate is issued by a trusted certificate authority, has not expired, and matches the server's hostname according to standard X.509 certificate validation procedures. However, the vulnerable versions of getmail bypass these essential verification steps, allowing any certificate to be accepted regardless of its legitimacy or trustworthiness. This flaw operates at the application layer of the OSI model and specifically affects the secure communication protocols used for email retrieval.
The operational impact of this vulnerability is severe and far-reaching for organizations relying on getmail for email processing. Attackers can exploit this weakness to intercept and potentially modify email communications between clients and IMAP servers, gaining access to sensitive information including login credentials, personal data, business communications, and confidential correspondence. The vulnerability enables passive eavesdropping attacks where malicious actors can silently monitor email traffic without detection, as well as active attacks where attackers can redirect communications to malicious servers. This compromises the fundamental security assurances that SSL/TLS encryption is designed to provide, essentially rendering the secure connection meaningless from a threat perspective.
Organizations affected by this vulnerability should immediately upgrade to getmail versions that properly implement X.509 certificate validation and disable the vulnerable IMAP-over-SSL functionality until proper security measures are in place. The mitigation strategy should include implementing proper certificate validation mechanisms that align with industry standards such as those specified in the OpenSSL library and PKI best practices. Security administrators should also consider implementing network-level monitoring to detect unusual certificate behavior and establish proper certificate management procedures. From an ATT&CK framework perspective, this vulnerability maps to T1041 (Exfiltration Over C2 Channel) and T1566 (Phishing) as attackers can use this weakness to facilitate data exfiltration and credential theft. The vulnerability also aligns with CWE-295 (Improper Certificate Validation) which specifically addresses the failure to properly validate certificates in secure communications. Organizations should also consider implementing certificate pinning mechanisms and regularly audit their email infrastructure to ensure proper SSL/TLS implementation and prevent similar vulnerabilities from emerging in other components of their email security stack.