CVE-2012-3742 in iOS
Summary
by MITRE
Safari in Apple iOS before 6 does not properly restrict use of an unspecified Unicode character that looks similar to the https lock indicator, which allows remote attackers to spoof https connections by placing this character in the TITLE element of a web page.
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Analysis
by VulDB Data Team • 04/13/2021
The vulnerability described in CVE-2012-3742 represents a sophisticated user interface deception attack targeting Apple iOS devices running versions prior to iOS 6. This flaw exploits the visual similarity between a legitimate https security indicator and a Unicode character that visually resembles the lock icon used to signify secure connections. The vulnerability specifically affects Safari web browser implementations on iOS devices, creating a significant security risk for users who rely on visual indicators to verify website authenticity and secure communication channels. The issue stems from Safari's insufficient validation of Unicode characters within web page elements, particularly the TITLE element, which allows malicious actors to manipulate visual security cues.
The technical implementation of this vulnerability involves the exploitation of Unicode character similarity rather than traditional cryptographic weaknesses. Attackers can inject a Unicode character that visually mimics the https lock icon, creating the illusion of a secure connection when in reality the web page may be compromised or the connection may be unencrypted. This character manipulation occurs within the TITLE element of web pages, which is a common HTML element used to define document titles and often displayed in browser tabs and bookmarks. The vulnerability demonstrates a failure in input validation and character rendering processes within Safari's web rendering engine, allowing malicious content to bypass normal security checks that should prevent such visual deception attacks.
From an operational perspective, this vulnerability creates substantial risk for users conducting sensitive online activities such as banking, e-commerce transactions, or accessing confidential information. The attack vector is particularly dangerous because it relies on user trust in visual security indicators, making it difficult for average users to detect the deception. When users see what appears to be a secure connection indicator, they may unknowingly proceed with sensitive activities while their communications remain vulnerable to interception or manipulation. This vulnerability undermines the fundamental security principle of user confidence in visual security indicators and represents a significant downgrade in user security expectations for iOS devices before version 6. The impact extends beyond individual users to potentially affect enterprise security protocols and corporate data protection measures that rely on user trust in browser security indicators.
The mitigation strategies for this vulnerability include updating to iOS 6 or later versions where Apple implemented proper Unicode character validation and rendering restrictions. Users should also exercise heightened caution when browsing websites, particularly those requiring sensitive information input, and verify certificate details through alternative means beyond visual indicators. Security professionals should implement network monitoring to detect potential exploitation attempts and educate users about the importance of verifying certificate information through certificate panes rather than relying solely on visual lock icons. This vulnerability aligns with CWE-174, which addresses the weakness of insufficient character encoding validation, and relates to ATT&CK technique T1566.001 for credential harvesting through phishing attacks that exploit user trust in visual security indicators. Organizations should ensure comprehensive patch management programs to address such user interface deception vulnerabilities that can undermine the security foundation of mobile platforms.