CVE-2015-5857 in iOS
Summary
by MITRE
Mail in Apple iOS before 9 allows remote attackers to use an address-book contact as a spoofed e-mail sender address via unspecified vectors.
If you want to get the best quality for vulnerability data then you always have to consider VulDB.
Analysis
by VulDB Data Team • 06/16/2022
The vulnerability identified as CVE-2015-5857 represents a significant email spoofing weakness within Apple iOS mail handling mechanisms prior to version 9. This security flaw allows remote attackers to exploit the email client's address book integration to forge sender addresses, potentially enabling phishing attacks and social engineering campaigns that appear to originate from legitimate contacts within a user's address book. The vulnerability stems from insufficient validation of email sender information when displaying messages in the iOS mail application, creating a pathway for malicious actors to manipulate the perceived authenticity of incoming emails through the use of contact information.
The technical implementation of this vulnerability involves the iOS mail client's handling of email headers and address book integration. When users receive emails, the system displays sender information based on both the actual email headers and the user's address book contacts. Attackers can leverage this integration by crafting emails that reference contacts already present in the victim's address book, causing the mail client to display the spoofed sender address as if it originated from a trusted contact. This manipulation occurs through unspecified vectors that likely involve the manipulation of email header fields or the exploitation of how the iOS mail application processes and displays contact information within email messages.
The operational impact of CVE-2015-5857 extends beyond simple email spoofing to encompass broader security implications for iOS users and organizations relying on email-based communication. This vulnerability creates opportunities for sophisticated phishing campaigns where attackers can make emails appear to originate from colleagues, friends, or business partners, significantly increasing the likelihood of successful social engineering attacks. The vulnerability affects the fundamental trust model of email communication within iOS, potentially enabling attackers to bypass security measures that rely on sender verification and user familiarity with contact information.
From a cybersecurity framework perspective, this vulnerability aligns with CWE-284, which addresses improper access control in software applications, and represents a weakness in the email client's authorization mechanisms. The issue also relates to ATT&CK technique T1566, which covers phishing campaigns, particularly those involving spearphishing where attackers use legitimate contact information to increase the credibility of their attacks. Organizations and individual users affected by this vulnerability face increased risk of falling victim to targeted attacks that exploit the trust users place in their address book contacts, potentially leading to unauthorized access to sensitive systems or data breaches.
Mitigation strategies for CVE-2015-5857 require immediate patching of affected iOS versions to the latest available updates from Apple, which address the underlying email handling logic and implement proper validation of sender information. Users should also exercise heightened caution when opening emails from contacts whose addresses appear legitimate but whose communication patterns seem unusual. Security awareness training programs should emphasize the importance of verifying email authenticity through multiple methods beyond the sender address, including checking email headers and confirming communication through alternative channels. Organizations should implement email security solutions that provide additional layers of protection against spoofing attacks and consider deploying email authentication protocols such as DKIM and DMARC to strengthen their email security posture.