CVE-2016-7199 in Internet Explorer
Summary
by MITRE
Microsoft Internet Explorer 9 through 11 and Microsoft Edge allow remote attackers to bypass the Same Origin Policy and obtain sensitive window-state information via a crafted web site, aka "Microsoft Browser Information Disclosure Vulnerability."
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Analysis
by VulDB Data Team • 09/30/2022
The vulnerability identified as CVE-2016-7199 represents a critical security flaw in Microsoft's web browsers that affects Internet Explorer versions 9 through 11 and Microsoft Edge. This issue enables remote attackers to circumvent the fundamental Same Origin Policy that serves as a cornerstone of web security architecture. The vulnerability specifically allows malicious actors to access sensitive window-state information that should normally be restricted to prevent cross-site information leakage. The Same Origin Policy is a critical security mechanism defined by the World Wide Web Consortium and implemented across all modern browsers to prevent unauthorized access to resources from different origins. This particular vulnerability creates an exploitable pathway that undermines the browser's security model by enabling information disclosure that violates core web security principles.
The technical flaw manifests through a crafted web page that manipulates browser behavior to access window state information that should be isolated between different origins. This vulnerability operates at the browser rendering engine level, specifically targeting how Internet Explorer and Edge handle cross-origin resource access and window object interactions. Attackers can leverage this weakness to gather sensitive information about the user's browsing context, including window dimensions, location data, and potentially other state information that could be used in conjunction with other attacks. The exploitation technique involves constructing malicious web content that triggers the browser to expose window state data through improper access controls. This type of vulnerability falls under the CWE-200 category of "Information Exposure" and specifically relates to the improper handling of cross-origin resource sharing mechanisms. The attack vector is particularly dangerous because it requires no user interaction beyond visiting a malicious website, making it a passive information disclosure threat.
The operational impact of this vulnerability extends beyond simple information disclosure, as the leaked window-state information could provide attackers with valuable context for more sophisticated attacks. The exposed data might include browser window positioning, size information, and other state attributes that could be used to enhance social engineering attacks or to gather intelligence about the user's browsing environment. This information could potentially be combined with other vulnerabilities to create more effective phishing campaigns or to refine attacks against specific browser configurations. The vulnerability affects a broad range of Microsoft browsers and operating systems, making it particularly concerning for enterprise environments where multiple browser versions might be in use. Security researchers have noted that this type of information disclosure vulnerability can serve as a stepping stone for more complex attacks, as the leaked data provides attackers with additional context for crafting targeted exploits. The vulnerability's impact is further amplified by the fact that it affects both legacy Internet Explorer versions and the newer Edge browser, indicating a fundamental flaw in the browser's security architecture that spans multiple generations of Microsoft's web platform.
Mitigation strategies for CVE-2016-7199 should focus on immediate patching of affected systems and implementation of additional security controls. Microsoft released security updates that addressed this vulnerability through patches to Internet Explorer and Edge browsers, and organizations should ensure all affected systems are updated promptly. Network-level mitigations can include implementing web application firewalls that monitor for suspicious cross-origin access patterns and content filtering that blocks known malicious domains. Browser hardening techniques should be applied to restrict cross-origin functionality and implement additional security headers that further constrain information disclosure. Organizations should also consider implementing monitoring solutions that can detect anomalous browser behavior indicative of exploitation attempts. The vulnerability demonstrates the importance of maintaining up-to-date security patches and implementing defense-in-depth strategies that provide multiple layers of protection against information disclosure threats. Security teams should conduct regular vulnerability assessments to identify similar weaknesses in browser configurations and ensure that the Same Origin Policy remains properly enforced across all web browsing activities. This vulnerability also highlights the need for continuous security monitoring and the importance of adhering to security standards such as those defined by the Open Web Application Security Project and the Center for Internet Security benchmarks.