#VU51665 Security restrictions bypass in Mozilla Firefox - CVE-2021-23985

Description

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.

Remediation

External links

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