CVE-2018-20067 in Chrome
Summary
by MITRE
A renderer initiated back navigation was incorrectly allowed to cancel a browser initiated one in Navigation in Google Chrome prior to 71.0.3578.80 allowed a remote attacker to confuse the user about the origin of the current page via a crafted HTML page.
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Analysis
by VulDB Data Team • 04/27/2020
This vulnerability represents a critical navigation manipulation flaw in Google Chrome's browser engine that exploited the improper handling of back navigation sequences during page transitions. The issue occurred when a renderer process initiated a back navigation action that was incorrectly permitted to override or cancel an already initiated browser-initiated navigation, creating a scenario where user navigation behavior could be manipulated without their knowledge or consent. The vulnerability specifically affected Chrome versions prior to 71.0.3578.80, where the security boundaries between renderer and browser processes were insufficiently enforced during navigation operations.
The technical implementation of this flaw involved a race condition or improper state management within Chrome's navigation subsystem where the browser failed to properly distinguish between different types of navigation requests. When a malicious HTML page triggered a back navigation from the renderer process, the browser's navigation controller incorrectly processed this request as a legitimate override rather than rejecting it due to the conflicting nature of renderer-initiated cancellation of browser-initiated navigation. This misclassification allowed attackers to manipulate the browser's navigation stack in ways that could deceive users about the true origin of the currently displayed page.
The operational impact of this vulnerability created significant user confusion and potential security risks for victims who might be tricked into believing they were visiting a legitimate website when in fact they were viewing content from a malicious source. Attackers could craft HTML pages that would cause the browser to navigate back to a previously visited page while simultaneously displaying content from the malicious site, effectively creating a deceptive user experience. This manipulation could be particularly dangerous in phishing scenarios where users might be led to believe they were on a trusted site while actually interacting with an attacker-controlled page, potentially leading to credential theft or other malicious activities.
The vulnerability aligns with CWE-691, which addresses inadequate protection of navigation and control flow, and can be mapped to ATT&CK technique T1059.001 for the execution of malicious code through web-based interfaces. The flaw demonstrates a classic example of improper input validation and process separation where the renderer process was granted inappropriate privileges to interfere with browser-level navigation operations. Security researchers identified that this issue stemmed from insufficient validation of navigation request origins and types within Chrome's browser engine, particularly in the interaction between the renderer and browser processes during complex navigation scenarios. The fix implemented in Chrome 71.0.3578.80 involved strengthening the navigation request validation logic and improving the isolation between renderer and browser processes to prevent unauthorized interference with browser-initiated navigation sequences.
This vulnerability highlighted the importance of maintaining strict security boundaries between different browser processes and demonstrated how seemingly minor navigation handling issues could be exploited to create significant user deception scenarios. The remediation focused on improving the browser's navigation stack management and ensuring that only appropriate navigation requests could modify the browser's current navigation state, thereby preventing malicious actors from manipulating user perception through crafted HTML content. The incident underscored the critical need for comprehensive testing of inter-process communication pathways and proper validation of navigation request types within browser security architectures.