CVE-2017-13860 in macOS
Summary
by MITRE
An issue was discovered in certain Apple products. iOS before 11.2 is affected. macOS before 10.13.2 is affected. The issue involves the "Mail Drafts" component. It allows man-in-the-middle attackers to read e-mail content by leveraging mishandling of S/MIME credential encryption.
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Analysis
by VulDB Data Team • 08/18/2024
The vulnerability identified as CVE-2017-13860 represents a critical security flaw within Apple's mail application ecosystem affecting multiple operating systems. This weakness specifically targets the Mail Drafts functionality across iOS versions prior to 11.2 and macOS versions before 10.13.2, creating a significant exposure for users who rely on S/MIME encrypted email communications. The issue stems from improper handling of S/MIME credential encryption within the email client's draft management system, which creates opportunities for attackers to intercept and access sensitive email content during transmission.
The technical exploitation of this vulnerability occurs through man-in-the-middle attack vectors where malicious actors can position themselves between communicating parties to capture and decrypt email content. This flaw operates at the cryptographic protocol level, specifically targeting how the Mail application manages S/MIME certificates and encryption keys when storing email drafts. The mishandling of credential encryption means that sensitive information stored in draft emails becomes accessible to unauthorized parties who can exploit this weakness to gain unauthorized access to confidential communications. This vulnerability directly maps to CWE-310, which addresses cryptographic weaknesses and improper handling of encryption credentials, making it particularly dangerous for enterprise environments where sensitive data is routinely transmitted through email channels.
The operational impact of this vulnerability extends beyond simple privacy concerns to encompass potential data breaches and compromise of sensitive business communications. Organizations relying on Apple Mail for S/MIME encrypted communications face significant risk exposure when systems remain unpatched, as attackers can systematically intercept and read draft emails containing confidential information. The vulnerability affects not only individual users but also enterprise environments where email drafts often contain preliminary communications, strategic discussions, or sensitive business information that could be exploited for competitive advantage or financial gain. This weakness particularly impacts sectors requiring strict email security protocols such as finance, healthcare, and government communications.
Security professionals should prioritize immediate patching of affected systems to mitigate this vulnerability, as the window for exploitation remains open until proper updates are deployed. The remediation process requires updating to iOS 11.2 or later and macOS 10.13.2 or later versions where Apple has implemented proper S/MIME credential handling mechanisms. Organizations should also consider implementing additional network monitoring to detect potential man-in-the-middle attacks and establish secure communication protocols that do not rely solely on the vulnerable mail draft functionality. This vulnerability aligns with ATT&CK technique T1566, which covers credential harvesting through man-in-the-middle attacks, emphasizing the need for comprehensive network security measures beyond simple patch management.