CVE-2021-4098: 
vulnerability analysis and mitigation

Insufficient data validation in Mojo in Google Chrome prior to version 96.0.4664.110 was identified as CVE-2021-4098. The vulnerability allowed a remote attacker who had compromised the renderer process to potentially perform a sandbox escape through a crafted HTML page. This critical security flaw was discovered and reported by Sergei Glazunov of Google Project Zero on October 26, 2021 (Chrome Release).

The vulnerability received a CVSS v3.1 base score of 7.4 (High), with the vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:N/I:H/A:N. This indicates that the vulnerability can be exploited over the network, requires low attack complexity, needs no privileges, but does require user interaction. The scope is changed, and while there is no impact on confidentiality or availability, the impact on integrity is high (NVD).

The vulnerability could allow an attacker to escape the Chrome sandbox if they had already compromised the renderer process. This represents a significant security breach as it could potentially lead to executing code outside of Chrome's protective sandbox environment (Chrome Release).

Google addressed this vulnerability in Chrome version 96.0.4664.110 for Windows, Mac, and Linux platforms. Users are advised to update their Chrome browsers to this version or later to protect against this security flaw (Chrome Release).