Security restrictions bypass in Mozilla Firefox - CVE-2021-23985

Vulnerability details

The vulnerability allows a local user to gain access to sensitive information.

The vulnerability exists due to application does not properly impose security restrictions. If an attacker is able to alter specific about:config values (for example malware running on the user's computer), the Devtools remote debugging feature could have been enabled in a way that was unnoticable to the user. This would have allowed a remote attacker (able to make a direct network connection to the victim) to monitor the user's browsing activity and (plaintext) network traffic. This was addressed by providing a visual cue when Devtools has an open network socket.

Affected software

How to mitigate CVE-2021-23985

External References

• https://www.mozilla.org/en-US/security/advisories/mfsa2021-10/

Related Security Bulletins

• Multiple vulnerabilities in Mozilla Firefox and Firefox ESR
• Gentoo update for Mozilla Firefox
• Ubuntu update for firefox