**CRITICAL RISK** CVE-2023-4762 Google Chrome < v116.0.5845.179 – Arbitrary Code Execution (RCE) via Exploit of Type Confusion Vulnerability in V8 JavaScript Engine

Background & Context

Google Chrome is a web browser developed by Google. It was first released in 2008 for Microsoft Windows, built with free software components from Apple WebKit and Mozilla Firefox. Versions were later released for Linux, macOS, iOS, and also for Android, where it is the default browser. The browser is also the main component of ChromeOS, where it serves as the platform for web applications.

V8 is a free and open-source JavaScript and WebAssembly engine developed by the Chromium Project for Chromium and Google Chrome web browsers. The V8 JavaScript engine has features such as dynamic code generation, hidden class transitions, and precise garbage collection.


Vulnerability Summary

A “type confusion” vulnerability exists in V8 in versions of Google Chrome prior to 116.0.5845.179, which can be triggered when visiting a maliciously crafted HTML page.

Chrome is vulnerable because it allocates or initializes a resource such as a pointer, object, or variable using one type, but it later accesses that resource using a type that is incompatible with the original type. When Chrome accesses the resource using an incompatible type, this could trigger logical errors because the resource does not have expected properties. In languages without memory safety, such as C and C++, type confusion can lead to “out-of-bounds” memory access.


Impact If Exploited

Exploit allows a remote attacker to execute arbitrary code via the out-of-bound read. By reading out-of-bounds memory, an attacker might be able to get secret values, such as memory addresses, which can be used to bypass protection mechanisms such as ASLR in order to improve the reliability and likelihood of exploiting a separate weakness to achieve arbitrary code execution.

NOTE: This vulnerability has been reported by the CISA (America’s Cyber Defense Agency) to be known to be currently actively exploited in the wild as of 2024-02-06. There are reports that an exploit chain incorporating CVE-2023-4762 in combination with other vulnerabilities has been used to install ‘Predator’ spyware surreptitiously onto Android and iOS devices, from at least as early as September 2023. The exploit chain leveraged a set of three vulnerabilities – CVE-2023-41991, CVE-2023-41992, and CVE-2023-41993 – which could allow a malicious actor to bypass certificate validation, elevate privileges, and achieve remote code execution on targeted devices.

In the initial ‘zero-day’ exploit, a joint investigation conducted by the Canadian interdisciplinary laboratory and Google’s Threat Analysis Group (TAG) indicated that the attack originally targeted an Egyptian presidential candidate, leveraged the national mobile phone network provider, and are believed to have been conducted by the Egyptian government itself. However, proof of Concept (PoC) exploits have since been made widely available to attackers via sites such as GitHub, so any organisation using the vulnerable software is now potentially at risk. Prioritisation should therefore be given to remediation in any impacted environment.


Affected Product Versions

  • Google Chrome < v116.0.5845.179;
  • Microsoft Edge (Chromium-Based) < v116.0.1938.76; and
  • (Potentially other Chromium-based browsers including Brave, Falkon, Bromite, Blisk, Epic, Opera, Vivaldi, and more.)



Official Fix & Remediation Guidance

Customers are advised to upgrade to the latest version of Chrome or other Chromium-based browser impacted. The fix for chrome is available in the September 2009 Stable Channel Update for Desktop. Guidance on how to update Chrome can be found in the Google Knowledge Base article, at https://support.google.com/chrome/answer/95414 .

NOTE: Remediation of this vulnerability by patching to a specific version indicated may not be sufficient to secure the product against further vulnerabilities discovered in later versions, subsequent to the publication of this guidance. Unless contra-indicated, customers are therefore advised to always upgrade to the latest version of the product available.


Temporary Mitigation & Workarounds:

(The vendor has not advised of any alternative temporary mitigation or workarounds)

NOTE: Caution should always be taken in applying any temporary mitigations listed. Mitigations are only recommended in cases where patches to remediate the vulnerability are not available or cannot safely be applied to a given environment immediately. A given mitigation may not in all cases be recommended officially by the application vendor. The viability of any given temporary mitigation measure may vary, depending on server platform and existing configuration. Mitigations listed may incompletely remediate any given vulnerability. Configuration changes to implement listed mitigations may impact/disrupt required functionality within a given customer application. Care should therefore be taken to carefully analyse any listed mitigations for appropriateness to a given environment. Customers are advised to test any configuration changes prior to their being introduced into a production environment.




Category: Arbitrary Code Execution


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