#VU57883 Improper Restriction of Rendered UI Layers or Frames in Mozilla Firefox and Firefox ESR

Published: 2021-11-02

Vulnerability identifier: #VU57883

Vulnerability risk: Low


CVE-ID: CVE-2021-38509

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 incorrect processing of an unusual sequence of attacker-controlled events. A remote attacker can display a Javascript alert() dialog with arbitrary (although unstyled) contents over top of arbitrary webpage of the attacker's choosing.

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

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