CVE-2016-4751 in Safari
Summary
by MITRE
The Safari Tabs component in Apple Safari before 10 allows remote attackers to spoof the address bar of a tab via a crafted web site.
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Analysis
by VulDB Data Team • 09/21/2022
The vulnerability identified as CVE-2016-4751 represents a critical security flaw in Apple Safari's tab management system that existed prior to version 10. This issue specifically affects the Safari Tabs component and enables remote attackers to execute address bar spoofing attacks against users. The flaw stems from insufficient validation mechanisms within Safari's tab interface that fail to properly verify the authenticity of web content displayed in the address bar of individual tabs. Attackers can craft malicious websites that manipulate the visual representation of the address bar, creating a false sense of security for unsuspecting users who may believe they are visiting a legitimate domain when in fact they are interacting with malicious content.
This vulnerability operates at the user interface level of the browser, specifically targeting the tab-based navigation system that allows users to manage multiple web pages simultaneously. The technical implementation flaw lies in how Safari processes and displays URL information within tab headers and address bar elements when multiple tabs are open. The system fails to properly distinguish between legitimate navigation updates and maliciously constructed URL representations that can be injected through crafted web content. This weakness creates a scenario where attackers can exploit the browser's tab management functionality to present deceptive address bar information that does not accurately reflect the actual origin of the web content being displayed.
The operational impact of CVE-2016-4751 extends beyond simple visual deception, potentially enabling sophisticated phishing attacks and credential theft operations. Users operating Safari browsers before version 10 may be misled into believing they are visiting trusted websites when they are actually interacting with malicious domains that have successfully spoofed the address bar presentation. This vulnerability particularly affects users who frequently maintain multiple tabs open simultaneously, as the spoofed address bar information can be particularly convincing when combined with other social engineering techniques. The attack vector requires no special privileges or complex exploitation methods, making it accessible to threat actors with basic web development knowledge.
From a cybersecurity perspective, this vulnerability aligns with CWE-601 and CWE-79 concepts related to URL redirection and cross-site scripting vulnerabilities, while also mapping to ATT&CK techniques involving credential access and phishing operations. The flaw essentially undermines the browser's ability to provide users with accurate domain information, which is fundamental to establishing trust in web communications. Organizations and individuals using affected Safari versions face increased risk of falling victim to targeted phishing campaigns that exploit this address bar spoofing capability. The vulnerability demonstrates how interface-level security flaws can have significant implications for user trust and security posture, particularly in environments where users rely heavily on tab-based browsing for productivity tasks.
Mitigation strategies for CVE-2016-4751 primarily focus on immediate software updates to Safari version 10 or later, which incorporates proper validation mechanisms for tab address bar display. Users should also implement additional security measures including browser security extensions, regular security updates, and user education about recognizing potential phishing attempts. Organizations should ensure their Safari browser management policies include mandatory update procedures and consider implementing additional security controls such as web filtering solutions that can detect and block suspicious URL patterns. The vulnerability highlights the importance of maintaining current browser versions and demonstrates how seemingly minor interface flaws can create significant security risks in web browsing environments.