CVE-2013-0289 in Isync
Summary
by MITRE
Isync 0.4 before 1.0.6, does not verify that the server hostname matches a domain name in the subject s Common Name (CN) or subjectAltName field of the X.509 certificate, which allows man-in-the-middle attackers to spoof SSL servers via an arbitrary valid certificate.
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Analysis
by VulDB Data Team • 03/21/2022
The vulnerability described in CVE-2013-0289 affects the isync email synchronization tool version 0.4 and earlier, specifically before version 1.0.6. This represents a critical security flaw in the SSL/TLS certificate verification process that undermines the fundamental security assurances provided by public key infrastructure. The issue stems from the application's failure to properly validate server certificates against the expected hostname, creating a significant attack surface for malicious actors seeking to compromise secure communications.
The technical flaw resides in the certificate validation mechanism where isync does not perform proper hostname verification against the X.509 certificate presented by the SSL server. According to industry standards and RFC 2818, when establishing SSL connections, applications must verify that the certificate's subject common name or subject alternative name fields contain a domain name that matches the hostname being connected to. This verification ensures that clients are communicating with the intended server and not an imposter. The absence of this validation creates a man-in-the-middle attack vector where attackers can present any valid certificate to establish a false SSL connection, effectively bypassing the security controls designed to prevent unauthorized access to email servers.
The operational impact of this vulnerability is severe and far-reaching within email security contexts. Attackers can exploit this weakness to intercept, modify, or steal email communications between users and their mail servers. This compromise extends beyond simple eavesdropping to include potential credential theft, data exfiltration, and the ability to inject malicious content into email streams. The vulnerability particularly affects users who rely on isync for connecting to corporate or personal email servers, as it undermines the trust model that SSL/TLS certificates are designed to establish. This weakness can be exploited in various attack scenarios including public Wi-Fi network interception, compromised network infrastructure, or targeted attacks against specific users or organizations.
Organizations and individuals using affected versions of isync should immediately upgrade to version 1.0.6 or later to address this vulnerability. The fix implemented in the updated version properly enforces hostname validation against certificate subject fields, aligning with established security practices and industry standards. Additional mitigations may include implementing network-level security controls such as firewall rules to restrict access to email servers, deploying network monitoring to detect anomalous certificate behavior, and conducting regular security assessments to identify other potentially vulnerable applications. This vulnerability also highlights the importance of maintaining up-to-date security software and following security best practices for certificate management and validation. From an ATT&CK framework perspective, this vulnerability maps to techniques involving credential access through network sniffing and man-in-the-middle attacks, while the CWE classification would fall under CWE-295 which specifically addresses improper certificate validation in security protocols.