An emergency security update has been released by Google for Chrome stable channel for desktop for Windows, Mac, and Linux. This is the first emergency update released so far in 2023 to patch an actively exploited zero-day vulnerability in Google Chrome’s desktop application. The updated version v112.0.5615.121 also includes other security fixes deemed necessary from internal audits, fuzzing, and other initiatives, however no other vulnerabilities are patched in this update.  

The zero-day vulnerability CVE-2023-2033 is a type confusion flaw found in the V8 engine, an open-source JavaScript and WebAssembly engine used by Google Chrome and other Chromium-based browsers responsible for executing JavaScript code. This vulnerability has been rated as high severity by Google in their security update releases post, however a CVSS base score rating has not yet been assigned. Type confusion flaws tend to result in a resource, which could be a pointer, object, or variable, being accessed by the product using an incompatible type, leading to logical errors and out-of-bounds memory access. An out-of-bounds read or write action in the memory buffer can then cause a crash of the system, or potentially lead to arbitrary code execution. The exploit for this Chromium vulnerability can be performed by a remote attacker through a heap corruption memory leak. This can be achieved by a specially crafted malicious HTML page being accessed by the vulnerable browser. 

Despite an exploit for this vulnerability being found in the wild, details about this attack, such as bug details, targets, and responsible threat actors, have not been released. It is important for all users to update their desktop Chrome application as soon as possible due to the active exploitation of this flaw. Users can check which version of Chrome is running on their device by click the three-dot menu at the top right of the browser window, and opening Settings, then choosing the About Chrome tab from the menu on the left. This will open a page which shows the current version of Chrome, and the option to update the browser if necessary. This is also the settings page where more information about automatic updates for Chrome can be accessed and turned on to keep your browser up to date in the future.