Download Firefox

Firefox is no longer supported on Windows 8.1 and below.

Please download Firefox ESR (Extended Support Release) to use Firefox.

Firefox is no longer supported on macOS 10.14 and below.

Please download Firefox ESR (Extended Support Release) to use Firefox.

Firefox Privacy Notice

Mozilla Foundation Security Advisory 2021-23

Security Vulnerabilities fixed in Firefox 89

Announced
June 1, 2021
Impact
high
Products
Firefox
Fixed in
  • Firefox 89

#CVE-2021-29965: Password Manager on Firefox for Android susceptible to domain spoofing

Reporter
Harshit Mahendra
Impact
high
Description

A malicious website that causes an HTTP Authentication dialog to be spawned could trick the built-in password manager to suggest passwords for the currently active website instead of the website that triggered the dialog.
This bug only affects Firefox for Android. Other operating systems are unaffected.

References

#CVE-2021-29960: Filenames printed from private browsing mode incorrectly retained in preferences

Reporter
Sebastian Hengst
Impact
moderate
Description

Firefox used to cache the last filename used for printing a file. When generating a filename for printing, Firefox usually suggests the web page title. The caching and suggestion techniques combined may have lead to the title of a website visited during private browsing mode being stored on disk.

References

#CVE-2021-29961: Firefox UI spoof using "<select>" elements and CSS scaling

Reporter
Irvan Kurniawan
Impact
moderate
Description

When styling and rendering an oversized &lt;select> element, Firefox did not apply correct clipping which allowed an attacker to paint over the user interface.

References

#CVE-2021-29963: Shared cookies for search suggestions in private browsing mode

Reporter
Wladimir Palant working with Include Security
Impact
moderate
Description

Address bar search suggestions in private browsing mode were re-using session data from normal mode.
This bug only affects Firefox for Android. Other operating systems are unaffected.

References

#CVE-2021-29964: Out of bounds-read when parsing a "WM_COPYDATA" message

Reporter
Ronald Crane
Impact
moderate
Description

A locally-installed hostile program could send WM_COPYDATA messages that Firefox would process incorrectly, leading to an out-of-bounds read.
This bug only affects Firefox on Windows. Other operating systems are unaffected.

References

#CVE-2021-29959: Devices could be re-enabled without additional permission prompt

Reporter
Jan-Ivar Bruaroey
Impact
low
Description

When a user has already allowed a website to access microphone and camera, disabling camera sharing would not fully prevent the website from re-enabling it without an additional prompt. This was only possible if the website kept recording with the microphone until re-enabling the camera.

References

#CVE-2021-29962: No rate-limiting for popups on Firefox for Android

Reporter
Wladimir Palant working with Include Security
Impact
low
Description

Firefox for Android would become unstable and hard-to-recover when a website opened too many popups.
This bug only affects Firefox for Android. Other operating systems are unaffected.

References

#CVE-2021-29967: Memory safety bugs fixed in Firefox 89 and Firefox ESR 78.11

Reporter
Mozilla developers and community
Impact
high
Description

Mozilla developers Christian Holler, Anny Gakhokidze, Alexandru Michis, Gabriele Svelto reported memory safety bugs present in Firefox 88 and Firefox ESR 78.11. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code.

References

#CVE-2021-29966: Memory safety bugs fixed in Firefox 89

Reporter
Mozilla developers and community
Impact
moderate
Description

Mozilla developers Christian Holler, Tooru Fujisawa, Tyson Smith reported memory safety bugs present in Firefox 88. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code.

References