CVE-2011-3046 in Safari
Summary
by MITRE
The extension subsystem in Google Chrome before 17.0.963.78 does not properly handle history navigation, which allows remote attackers to execute arbitrary code by leveraging a "Universal XSS (UXSS)" issue.
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Analysis
by VulDB Data Team • 03/24/2021
The vulnerability identified as CVE-2011-3046 represents a critical security flaw within Google Chrome's extension subsystem that existed prior to version 17.0.963.78. This issue stems from improper handling of history navigation mechanisms within the browser's extension architecture, creating a pathway for remote attackers to exploit what is classified as a Universal Cross-Site Scripting (UXSS) vulnerability. The flaw specifically targets the way Chrome processes navigation events when users interact with browser history, particularly in scenarios involving extension contexts. Such vulnerabilities are particularly dangerous because they can bypass traditional security boundaries and execute malicious code with the privileges of the victim's browser session. The vulnerability's classification aligns with CWE-79 which addresses cross-site scripting flaws, and it demonstrates how extension subsystems can become attack vectors when not properly secured against navigation-based exploits. The UXSS nature of this vulnerability means that attackers can potentially bypass the same-origin policy that normally protects web applications from cross-site scripting attacks, making it especially perilous in the context of browser extensions where elevated privileges may be granted.
The technical implementation of this vulnerability involves the extension subsystem's failure to properly validate or sanitize history navigation events when extensions are active within the browser environment. When users navigate through browser history while extensions are loaded, Chrome's extension handling logic does not adequately separate or secure the extension context from the main browsing context. This creates a condition where malicious code embedded within extension manifests or extension content can be executed during history navigation events. The flaw essentially allows attackers to craft extension packages or manipulate existing extensions in such a way that when users navigate through their browser history, the malicious code within the extension executes with full browser privileges. This exploitation technique leverages the fact that extensions often have elevated permissions and can access sensitive browser APIs, making the successful exploitation particularly dangerous. The vulnerability's impact is amplified by the fact that Chrome extensions can access user data, cookies, and other sensitive information, creating a potential attack surface that extends far beyond simple script execution.
The operational impact of CVE-2011-3046 extends beyond simple code execution to encompass significant data compromise and system integrity threats. Attackers who successfully exploit this vulnerability can potentially access user sessions, steal sensitive information, manipulate browser behavior, and even install additional malicious extensions. The vulnerability affects users who have extensions installed, making it particularly relevant in environments where users frequently interact with extensions or where extensions are automatically installed. This flaw creates an attack vector that can be leveraged through malicious websites or compromised extensions, potentially leading to persistent threats that survive browser restarts. The exploitation requires minimal user interaction beyond normal browsing behavior, making it particularly dangerous in phishing scenarios or when users unknowingly install compromised extensions. Security researchers have noted that such vulnerabilities often remain undetected for extended periods because they exploit legitimate browser functionality in unexpected ways, making them difficult to detect through standard security scanning mechanisms.
Mitigation strategies for CVE-2011-3046 primarily focus on immediate browser updates to versions that contain the necessary security patches. Users should ensure they are running Chrome version 17.0.963.78 or later, which includes fixes specifically addressing the history navigation handling within the extension subsystem. System administrators should implement strict extension management policies, including regular reviews of installed extensions and removal of unused or untrusted extensions. The vulnerability highlights the importance of maintaining current browser versions and following security best practices for extension management. Organizations should consider implementing browser security policies that limit extension installation privileges and monitor extension behavior. Additionally, users should exercise caution when installing extensions from untrusted sources and regularly review extension permissions. The fix implemented by Google addresses the core issue by properly validating history navigation events within extension contexts and ensuring that extension code execution is properly isolated from user navigation events. This aligns with the broader security principle of least privilege and proper input validation, which are fundamental concepts in both CWE and ATT&CK frameworks. Organizations should also consider implementing network monitoring to detect potential exploitation attempts and maintain regular security assessments of browser environments to identify similar vulnerabilities.