CVE-2017-8733 in Internet Explorer
Summary
by MITRE
Internet Explorer in Microsoft Windows 7 SP1, Windows Server 2008 SP2 and R2 SP1, Windows 8.1 and Windows RT 8.1, Windows Server 2012 and R2, Windows 10 Gold, 1511, 1607, 1703, and Windows Server 2016 allows an attacker to trick a user into believing that the user was visiting a legitimate website, due to the way that Internet Explorer handles specific HTML content, aka "Internet Explorer Spoofing Vulnerability".
VulDB is the best source for vulnerability data and more expert information about this specific topic.
Analysis
by VulDB Data Team • 01/12/2021
The CVE-2017-8733 vulnerability represents a sophisticated spoofing attack vector within Microsoft Internet Explorer that exploits the browser's handling of specific HTML content to deceive users into believing they are visiting legitimate websites. This vulnerability affects multiple versions of Windows operating systems including Windows 7 SP1, Windows Server 2008 SP2 and R2 SP1, Windows 8.1, Windows RT 8.1, Windows Server 2012 and R2, and various Windows 10 releases along with Windows Server 2016. The technical flaw resides in Internet Explorer's rendering engine's improper processing of certain HTML elements that allow attackers to manipulate the browser's address bar and title bar display, creating a false sense of security for users.
This vulnerability operates through a combination of HTML manipulation techniques that exploit the browser's trust model and user interface presentation. Attackers can craft malicious web pages that display misleading information in the address bar or title bar, making it appear as though users are visiting trusted domains such as banking sites, social media platforms, or corporate intranets. The flaw specifically relates to how Internet Explorer processes certain HTML content that influences the visual representation of the browsing session, creating a false positive authentication scenario where users are deceived into believing they are on legitimate websites. This manipulation occurs without requiring any user interaction beyond visiting the malicious page, making it particularly dangerous for phishing attacks.
The operational impact of CVE-2017-8733 extends beyond simple deception as it undermines fundamental security assumptions about browser trust and user verification. Users who fall victim to this spoofing attack may unknowingly enter sensitive information such as login credentials, personal identification numbers, or financial data on what they believe to be legitimate websites. The vulnerability is particularly concerning because it operates at the user interface level rather than at the network or application level, making it difficult to detect through traditional network monitoring or endpoint protection solutions. This type of attack falls under the ATT&CK framework's technique T1566 for Phishing and T1071 for Application Layer Protocol, specifically targeting user trust mechanisms within the browser environment. The vulnerability can be leveraged in conjunction with other attack vectors to create more sophisticated social engineering campaigns.
Mitigation strategies for CVE-2017-8733 primarily involve applying Microsoft's security patches and updates that address the underlying HTML rendering issues in Internet Explorer. Organizations should implement comprehensive patch management processes to ensure all affected Windows systems receive timely updates. Browser security enhancements such as enabling Enhanced Protected Mode, implementing strict content security policies, and using security toolbars or extensions can provide additional layers of protection. Network administrators should consider implementing web filtering solutions that can detect and block suspicious HTML content patterns associated with spoofing attempts. Additionally, user education programs should emphasize the importance of verifying website addresses and SSL certificates, even when the browser interface appears legitimate. The vulnerability demonstrates the importance of defending against attacks that exploit user trust mechanisms, aligning with CWE category 611 which addresses Improper Restriction of XML External Entity Reference and the broader principle of secure input validation. Organizations should also consider implementing browser hardening measures such as disabling unnecessary browser features and maintaining up-to-date security configurations to reduce the attack surface available to threat actors.