CVE-2018-18347 in Chrome
Summary
by MITRE
Incorrect handling of failed navigations with invalid URLs in Navigation in Google Chrome prior to 71.0.3578.80 allowed a remote attacker to trick a user into executing javascript in an arbitrary origin via a crafted HTML page.
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Analysis
by VulDB Data Team • 06/18/2023
This vulnerability resides in the navigation handling mechanism of google chrome browser affecting versions prior to 71.0.3578.80. The flaw manifests when the browser encounters failed navigations involving invalid urls, creating a potential security loophole that could be exploited by remote attackers. The core technical issue stems from improper validation and handling of malformed url inputs during the navigation process, which allows malicious actors to manipulate the browser's navigation flow. The vulnerability is categorized under cwe-20 as improper input validation, specifically involving url parsing and navigation handling within the browser's core rendering engine. This weakness enables attackers to craft malicious html pages that can trick users into executing javascript code with arbitrary origins, bypassing normal security boundaries that should protect against cross-origin script execution.
The operational impact of this vulnerability extends beyond simple script execution, as it represents a significant bypass of the browser's security model. When users navigate to crafted pages containing invalid urls, the browser's navigation system fails to properly isolate or validate the execution context, allowing javascript code to run in contexts where it would normally be restricted. This creates a potential vector for cross-site scripting attacks, session hijacking, and other malicious activities that could compromise user data and browser integrity. The attack surface is particularly concerning as it leverages user trust in normal browsing behavior, making it difficult to detect and prevent through standard security measures. The vulnerability effectively undermines the browser's same-origin policy enforcement mechanisms, which are fundamental to web security architecture.
The exploitation of this vulnerability requires attackers to craft specific html pages that contain malformed urls designed to trigger the navigation failure condition. When users visit these pages, the browser's handling of the failed navigation creates an execution context where arbitrary javascript can be injected and executed. This technique can be particularly dangerous when combined with other attack vectors or when targeting specific user behaviors such as clicking on links or visiting compromised websites. The attack chain typically involves the attacker creating a page that forces the browser into a navigation state where it fails to properly validate the target url, then executing malicious javascript code that appears to originate from an unexpected or unauthorized source. This type of attack aligns with techniques documented in the attack pattern taxonomy under the category of client-side code injection attacks. The vulnerability demonstrates how seemingly minor flaws in url handling can create significant security implications when combined with user interaction patterns.
Mitigation strategies for this vulnerability primarily focus on updating to chrome versions 71.0.3578.80 or later where the navigation handling has been corrected. Organizations should implement comprehensive patch management processes to ensure all chrome installations are current with security updates. Browser security configurations can be enhanced by implementing stricter content security policies and disabling unnecessary javascript execution where possible. Network administrators should monitor for suspicious navigation patterns and implement web filtering solutions that can detect and block malicious url patterns. The fix implemented by google addresses the core navigation handling logic to properly validate url inputs and prevent the execution context from being manipulated during failed navigation scenarios. This represents a fundamental correction to the browser's url parsing and navigation security model, ensuring that failed navigation events do not create exploitable conditions for javascript execution. Security teams should also consider implementing user education programs to recognize potentially malicious web content and avoid visiting untrusted websites that may contain crafted navigation attacks.