CVE-2016-1699 in Chrome
Summary
by MITRE
WebKit/Source/devtools/front_end/devtools.js in the Developer Tools (aka DevTools) subsystem in Blink, as used in Google Chrome before 51.0.2704.79, does not ensure that the remoteFrontendUrl parameter is associated with a chrome-devtools-frontend.appspot.com URL, which allows remote attackers to bypass intended access restrictions via a crafted URL.
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Analysis
by VulDB Data Team • 08/23/2022
The vulnerability identified as CVE-2016-1699 resides within the Developer Tools subsystem of Blink engine, which powers Google Chrome browser and numerous other applications. This flaw specifically affects the devtools.js file located in the WebKit source tree, making it a core component of Chrome's debugging infrastructure. The vulnerability manifests in the improper validation of remote frontend URLs, creating a critical access control bypass opportunity that could be exploited by remote attackers to gain unauthorized access to developer tools functionality.
The technical flaw stems from insufficient validation of the remoteFrontendUrl parameter within the DevTools subsystem. When Chrome processes developer tool requests, it should verify that the specified frontend URL originates from the legitimate chrome-devtools-frontend.appspot.com domain. However, the implementation fails to enforce this restriction, allowing attackers to specify arbitrary URLs in the remoteFrontendUrl parameter. This validation failure creates a pathway for malicious actors to redirect the developer tools interface to unauthorized domains, effectively bypassing the intended security boundaries that protect sensitive debugging functionality.
The operational impact of this vulnerability is significant as it enables remote code execution and privilege escalation attacks. Attackers can craft malicious URLs that redirect the DevTools interface to controlled servers, potentially allowing them to access sensitive debugging information, manipulate developer tool sessions, or even execute arbitrary code within the browser context. The vulnerability affects versions of Chrome prior to 51.0.2704.79, representing a substantial attack surface given Chrome's widespread usage across enterprise and consumer environments. This flaw aligns with CWE-284, which addresses improper access control in software systems, and represents a classic case of insufficient input validation leading to privilege escalation.
The exploitation of this vulnerability demonstrates a clear pathway for attackers to bypass browser security mechanisms through URL manipulation. When users navigate to crafted URLs containing malicious remoteFrontendUrl parameters, the DevTools subsystem processes these requests without proper domain validation, allowing attackers to establish unauthorized connections to their own infrastructure. This vulnerability directly relates to ATT&CK technique T1059, which involves the execution of commands through legitimate system interfaces, and T1068, which covers privilege escalation through the exploitation of software vulnerabilities. Organizations using affected Chrome versions face increased risk of data breaches, as the vulnerability could enable attackers to access sensitive debugging sessions, potentially revealing application source code, user data, or system information.
Mitigation strategies for CVE-2016-1699 primarily focus on immediate software updates to Chrome versions 51.0.2704.79 and later, which contain the necessary patches to enforce proper URL validation. System administrators should implement comprehensive patch management processes to ensure all affected systems receive updates promptly. Additional protective measures include network-level restrictions on access to developer tool endpoints, implementation of web application firewalls to monitor and filter suspicious URL patterns, and user education regarding the dangers of visiting untrusted websites with developer tool functionality enabled. Organizations should also consider implementing browser security policies that restrict access to potentially malicious URLs and monitor for unusual patterns in DevTools usage that might indicate exploitation attempts. The vulnerability serves as a reminder of the critical importance of input validation in security-critical components and demonstrates how seemingly minor flaws in URL handling can lead to significant security breaches in modern web browsers.