#VU57882 Improper Restriction of Rendered UI Layers or Frames in Mozilla Firefox and Firefox ESR

Published: 2021-11-02

Vulnerability identifier: #VU57882

Vulnerability risk: Low

CVSSv3.1: 3.7 [CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:L/A:N/E:U/RL:O/RC:C]

CVE-ID: CVE-2021-38508

CWE-ID: CWE-1021

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
Mozilla Firefox
Client/Desktop applications / Web browsers
Firefox ESR
Client/Desktop applications / Web browsers

Vendor: Mozilla


The vulnerability allows a remote attacker to perform spoofing attack.

The vulnerability exists due to Firefox displays the form validity message in the correct location at the same time as a permission prompt (such as for geolocation). The validity message could have obscured the prompt, resulting in the user potentially being tricked into granting the permission.

Install updates from vendor's website.

Vulnerable software versions

Mozilla Firefox: 80.0 - 93.0

Firefox ESR: 91.0 - 91.2.0

External links

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.

Latest bulletins with this vulnerability