CVE-2017-9604 in KMail
Summary
by MITRE
KDE kmail before 5.5.2 and messagelib before 5.5.2, as distributed in KDE Applications before 17.04.2, do not ensure that a plugin's sign/encrypt action occurs during use of the Send Later feature, which allows remote attackers to obtain sensitive information by sniffing the network.
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Analysis
by VulDB Data Team • 12/08/2022
The vulnerability identified as CVE-2017-9604 affects KDE KMail and the underlying messagelib component versions prior to 5.5.2, which were distributed in KDE Applications versions before 17.04.2. This security flaw represents a critical weakness in the cryptographic handling of email communications within the KDE email client ecosystem. The vulnerability specifically manifests when users employ the Send Later feature, which allows them to schedule email transmission for a future time. The issue stems from the improper implementation of cryptographic operations within the email sending workflow, creating a window where sensitive information can be exposed during network transmission.
The technical flaw resides in the failure of the email client to properly enforce cryptographic signing and encryption actions when the Send Later feature is utilized. This represents a deviation from proper security implementation practices and can be classified under CWE-310 as Cryptographic Issues. The vulnerability creates an attack surface where network traffic can be intercepted and analyzed by malicious actors who are monitoring network communications. When users schedule emails to be sent later, the system should ensure that all cryptographic operations including digital signatures and encryption are properly applied before the message is stored for later transmission. However, the flaw allows these security measures to be bypassed or delayed until after the message has already been placed in the outgoing queue, making it vulnerable to network sniffing attacks.
The operational impact of this vulnerability is significant for users who rely on KDE KMail for secure communications. Attackers can exploit this weakness to intercept and read sensitive information contained within emails that have been scheduled for later delivery. This includes personal data, business confidential information, and any other sensitive content that would normally be protected by cryptographic measures. The vulnerability particularly affects organizations that depend on email encryption for compliance with data protection regulations and security policies. The attack vector requires only network monitoring capabilities, making it accessible to a wide range of threat actors from casual attackers to more sophisticated adversaries. This weakness undermines the fundamental security guarantees that users expect from encrypted email communications.
Mitigation strategies for CVE-2017-9604 primarily involve upgrading to patched versions of KDE Applications, specifically ensuring that both KMail and messagelib components are updated to version 5.5.2 or later. Organizations should implement immediate patch management procedures to address this vulnerability across their email infrastructure. Additionally, system administrators should consider implementing network monitoring to detect potential exploitation attempts and establish more robust email security policies. The vulnerability highlights the importance of proper cryptographic implementation in email clients and serves as a reminder of the critical need for thorough security testing of all email features, particularly those involving delayed operations. From an ATT&CK perspective, this vulnerability maps to T1041 as Exfiltration Over C2 Channel and T1566 as Phishing, as it enables attackers to obtain sensitive information through network interception techniques that would normally be prevented by proper cryptographic implementation.