CVE-2018-17477 in Chrome
Summary
by MITRE
Incorrect dialog placement in Extensions in Google Chrome prior to 70.0.3538.67 allowed a remote attacker to spoof the contents of extension popups via a crafted HTML page.
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Analysis
by VulDB Data Team • 06/06/2023
The vulnerability identified as CVE-2018-17477 represents a critical user interface spoofing flaw within Google Chrome's extension system that existed prior to version 70.0.3538.67. This issue specifically affected how Chrome handled dialog placements when displaying extension popups, creating a pathway for remote attackers to manipulate the visual presentation of extension interfaces. The flaw exploited a fundamental weakness in Chrome's extension rendering engine that failed to properly validate or isolate the display context of extension dialogs, allowing malicious web pages to manipulate how extension interfaces appeared to users. This vulnerability falls under the broader category of user interface redressing attacks that have been classified under CWE-691, which deals with insufficient control of a resource through a mechanism that allows access to a restricted resource.
The technical implementation of this vulnerability stemmed from improper handling of extension popup positioning within Chrome's browser architecture. When extensions displayed their user interfaces, the browser failed to maintain proper isolation between the extension's rendering context and the underlying web page content. Attackers could craft malicious HTML pages that would manipulate the placement and appearance of extension dialogs, causing legitimate extension interfaces to appear at incorrect locations or with modified content. This manipulation occurred through the exploitation of how Chrome's extension system managed z-index stacking contexts and positioning calculations for popup interfaces. The vulnerability specifically impacted the extension popup rendering pipeline, where the browser's extension manager would display interface elements without sufficient validation of their display parameters, creating opportunities for attackers to inject malicious content into extension dialogs.
The operational impact of this vulnerability extended beyond simple visual deception to potentially enable sophisticated phishing attacks and credential theft operations. Users could be deceived into believing they were interacting with legitimate extension interfaces while actually engaging with malicious content that appeared to be part of a trusted extension. This type of attack vector aligns with ATT&CK technique T1056.001 which covers input injection, specifically focusing on the manipulation of user interfaces to deceive users. The vulnerability could be particularly dangerous when combined with other attack vectors, as it allowed attackers to create convincing fake extension interfaces that could capture user input or redirect users to malicious websites. The flaw was especially concerning because it operated at the browser level, meaning it could affect any extension that displayed popups or user interfaces, potentially compromising the security of thousands of extensions that relied on standard Chrome popup behaviors.
Mitigation strategies for CVE-2018-17477 centered primarily on updating to Chrome version 70.0.3538.67 or later, which included comprehensive fixes to the extension popup rendering and positioning mechanisms. Security researchers recommended that organizations implement immediate patch management protocols to ensure all Chrome installations were updated to versions that addressed this vulnerability. The fix involved strengthening the validation of extension popup display parameters and implementing more robust isolation between extension interfaces and web page content. Additionally, users were advised to avoid visiting untrusted websites and to be vigilant when interacting with extension popups, particularly those that appeared at unusual locations or contained unexpected content. Organizations implementing browser security policies should have included mandatory Chrome updates as part of their security protocols, and security teams were advised to monitor for any attempts to exploit this vulnerability in the wild. The remediation process also highlighted the importance of maintaining current browser versions and implementing automated patch management systems to prevent similar vulnerabilities from being exploited. This vulnerability demonstrated the critical importance of secure user interface design in browser environments and reinforced the need for proper isolation mechanisms between different content contexts within browser applications.