Google released updates this week for Android and desktop Chrome browser users. These updates address high criticality zero-day vulnerabilities including one which has been actively exploited. This is the fourth Chrome update so far this year to patch zero-day vulnerabilities, with previous key updates being released in February, March, and April. Users should make sure they are using the most up to date version, which is Chrome 103 (103.0.5060.71) for Android, and 103.0.5060.114 for desktop, in order to make sure this patch has been applied. 

These updates contain patches for two zero-day vulnerabilities shared between the Android and desktop applications. The most important vulnerability patched in this update is CVE-2022-2294, a heap buffer overflow vulnerability in the Web Real-Time Communications (WebRTC) component. This vulnerability was reported by Avast Threat Intelligence team at the start of this month, and Google have confirmed that they are aware of active exploits for this vulnerability existing in the wild.  

Google Chrome have not released details of how this vulnerability has been exploited, claiming “Access to bug details and links may be kept restricted until a majority of users are updated with a fix”. Heap-based buffer overflow vulnerabilities often lead to application crashes, which can lead to denial of service (DoS) attacks. Execution of unauthorised code is also likely a component of this attack, as the buffer overflow means arbitrary code can be written into neighbouring memory portions. 

The second vulnerability patched for both Android and desktop users in this update is CVE-2022-2295. This is a type confusion vulnerability present in the V8 component. This has also been given a criticality rating of ‘High’, most likely due to attacks on type confusion vulnerabilities often allowing malicious code execution in memory layers. The desktop application update also includes a patch for another highly critical vulnerability, CVE-2022-2296. This is a use after free vulnerability that was found in the Chrome OS Shell, but it is not present in the Android version of Chrome. 

It is always best practice to update software as soon as possible whenever new updates are released, or to enable automatic software updates on your devices to do this for you. Desktop users of Chrome can check they are updated to the most recent version by going into ‘Settings’, and viewing the ‘About Chrome’ tab. This displays the current version of Chrome you are running and gives the option to update if a newer version is available.