CVE-2011-3243 in Safari
Summary
by MITRE
Cross-site scripting (XSS) vulnerability in WebKit, as used in Apple iOS before 5 and Safari before 5.1.1, allows remote attackers to inject arbitrary web script or HTML via vectors involving inactive DOM windows.
If you want to get the best quality for vulnerability data then you always have to consider VulDB.
Analysis
by VulDB Data Team • 11/24/2021
The CVE-2011-3243 vulnerability represents a critical cross-site scripting flaw within WebKit's implementation that affected Apple's iOS operating system prior to version 5 and Safari browser before version 5.1.1. This vulnerability falls under the CWE-79 category of Cross-Site Scripting, specifically targeting the browser's handling of DOM window objects. The flaw was particularly concerning because it leveraged inactive DOM windows as attack vectors, allowing malicious actors to execute arbitrary web scripts or HTML code in the context of a user's browsing session.
The technical exploitation of this vulnerability occurred through the improper handling of DOM window objects when they were not actively in use or visible to the user. WebKit's JavaScript engine failed to adequately sanitize or validate input when processing inactive window states, creating a pathway for attackers to inject malicious payloads that would execute when the window became active or when specific DOM events occurred. This particular weakness in the browser's security model allowed remote attackers to bypass standard XSS protection mechanisms that typically focus on active user input contexts.
The operational impact of this vulnerability was significant for users of affected Apple products, as it enabled attackers to perform a wide range of malicious activities including session hijacking, credential theft, and data exfiltration. Users could be tricked into visiting compromised websites that would silently execute malicious scripts in their browser context, potentially leading to unauthorized access to personal information, financial data, or corporate resources. The vulnerability was particularly dangerous because it could be exploited without requiring user interaction beyond visiting a malicious webpage, making it a prime target for drive-by download attacks and phishing campaigns.
This vulnerability aligns with several ATT&CK techniques including T1059.007 for Command and Scripting Interpreter: JavaScript and T1566 for Phishing, as attackers could craft malicious web pages that would exploit this flaw to execute arbitrary code on vulnerable systems. The attack surface was broad given the widespread use of Safari and iOS devices, making this vulnerability particularly attractive to threat actors seeking to maximize their impact. Organizations and individuals were advised to immediately update to patched versions of iOS and Safari to remediate this vulnerability, as the window of exposure for users remained significant until the security patches were applied.
Security researchers noted that the flaw was particularly insidious because it operated in the background without user awareness, making detection and prevention challenging. The vulnerability highlighted the importance of comprehensive input validation and proper state management in browser engines, as well as the need for continuous security auditing of core web technologies. The incident underscored the critical relationship between browser security and user safety, particularly in mobile environments where users often have less control over their software update processes compared to desktop systems.