Mozilla Foundation Security Advisory 2021-03

Security Vulnerabilities fixed in Firefox 85

Announced
January 26, 2021
Impact
high
Products
Firefox
Fixed in
  • Firefox 85

#CVE-2021-23953: Cross-origin information leakage via redirected PDF requests

Reporter
Rob Wu
Impact
high
Description

If a user clicked into a specifically crafted PDF, the PDF reader could be confused into leaking cross-origin information, when said information is served as chunked data.

References

#CVE-2021-23954: Type confusion when using logical assignment operators in JavaScript switch statements

Reporter
Gary Kwong
Impact
high
Description

Using the new logical assignment operators in a JavaScript switch statement could have caused a type confusion, leading to a memory corruption and a potentially exploitable crash.

References

#CVE-2021-23955: Clickjacking across tabs through misusing requestPointerLock

Reporter
Irvan Kurniawan
Impact
high
Description

The browser could have been confused into transferring a pointer lock state into another tab, which could have lead to clickjacking attacks.

References

#CVE-2021-23956: File picker dialog could have been used to disclose a complete directory

Reporter
Abdulrahman Alqabandi
Impact
moderate
Description

An ambiguous file picker design could have confused users who intended to select and upload a single file into uploading a whole directory. This was addressed by adding a new prompt.

References

#CVE-2021-23957: Iframe sandbox could have been bypassed on Android via the intent URL scheme

Reporter
Eliya Stein
Impact
moderate
Description

Navigations through the Android-specific intent URL scheme could have been misused to escape iframe sandbox.
Note: This issue only affected Firefox for Android. Other operating systems are unaffected.

References

#CVE-2021-23958: Screen sharing permission leaked across tabs

Reporter
Jan-Ivar Bruaroey
Impact
moderate
Description

The browser could have been confused into transferring a screen sharing state into another tab, which would leak unintended information.

References

#CVE-2021-23959: Cross-Site Scripting in error pages on Firefox for Android

Reporter
Muneaki Nishimura
Impact
moderate
Description

An XSS bug in internal error pages could have led to various spoofing attacks, including other error pages and the address bar.
Note: This issue only affected Firefox for Android. Other operating systems are unaffected.

References

#CVE-2021-23960: Use-after-poison for incorrectly redeclared JavaScript variables during GC

Reporter
Irvan Kurniawan
Impact
moderate
Description

Performing garbage collection on re-declared JavaScript variables resulted in a user-after-poison, and a potentially exploitable crash.

References

#CVE-2021-23961: More internal network hosts could have been probed by a malicious webpage

Reporter
Samy Kamkar, Ben Seri, and Gregory Vishnepolsky
Impact
moderate
Description

Further techniques that built on the slipstream research combined with a malicious webpage could have exposed both an internal network's hosts as well as services running on the user's local machine.

References

#CVE-2021-23962: Use-after-poison in <code>nsTreeBodyFrame::RowCountChanged</code>

Reporter
Chiaki ISHIKAWA
Impact
low
Description

Incorrect use of the RowCountChanged method could have led to a user-after-poison and a potentially exploitable crash.

References

#CVE-2021-23963: Permission prompt inaccessible after asking for additional permissions

Reporter
Paul Zühlcke
Impact
low
Description

When sharing geolocation during an active WebRTC share, Firefox could have reset the webRTC sharing state in the user interface, leading to loss of control over the currently granted permission

References

#CVE-2021-23964: Memory safety bugs fixed in Firefox 85 and Firefox ESR 78.7

Reporter
Mozilla developers and community
Impact
high
Description

Mozilla developers Andrew McCreight, Tyson Smith, Jesse Schwartzentruber, Jon Coppeard, Byron Campen, André Bargull, Steve Fink, Jason Kratzer, Christian Holler, Alexis Beingessner reported memory safety bugs present in Firefox 84 and Firefox ESR 78.6. 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-2021-23965: Memory safety bugs fixed in Firefox 85

Reporter
Mozilla developers and community
Impact
high
Description

Mozilla developers Sebastian Hengst, Christian Holler, Tyson Smith reported memory safety bugs present in Firefox 84. 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