Mozilla Foundation Security Advisory 2021-43

Security Vulnerabilities fixed in Firefox 93

Announced
October 5, 2021
Impact
high
Products
Firefox
Fixed in
  • Firefox 93

#CVE-2021-38496: Use-after-free in MessageTask

Reporter
Yangkang of 360 ATA Team
Impact
high
Description

During operations on MessageTasks, a task may have been removed while it was still scheduled, resulting in memory corruption and a potentially exploitable crash.

References

#CVE-2021-38497: Validation message could have been overlaid on another origin

Reporter
Irvan Kurniawan
Impact
moderate
Description

Through use of reportValidity() and window.open(), a plain-text validation message could have been overlaid on another origin, leading to possible user confusion and spoofing attacks.

References

#CVE-2021-38498: Use-after-free of nsLanguageAtomService object

Reporter
Yangkang of 360 ATA Team
Impact
moderate
Description

During process shutdown, a document could have caused a use-after-free of a languages service object, leading to memory corruption and a potentially exploitable crash.

References

#CVE-2021-32810: Data race in crossbeam-deque

Reporter
Maor Kleinberger
Impact
moderate
Description

In the crossbeam crate, one or more tasks in the worker queue could have been be popped twice instead of other tasks that are forgotten and never popped. If tasks are allocated on the heap, this could have caused a double free and a memory leak.

References

#CVE-2021-38500: Memory safety bugs fixed in Firefox 93, Firefox ESR 78.15, and Firefox ESR 91.2

Reporter
Mozilla developers
Impact
high
Description

Mozilla developers and community members Andreas Pehrson and Christian Holler reported memory safety bugs present in Firefox 92 and Firefox ESR 91.1. 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

#MOZ-2021-0008: Use-after-free in HTTP2 Session object

Reporter
Julien Cristau
Impact
high
Description

A use-after-free could have occured when an HTTP2 session object was released on a different thread, leading to memory corruption and a potentially exploitable crash.
Note: This issue is pending a CVE assignment and will be updated when available.

References

#CVE-2021-38501: Memory safety bugs fixed in Firefox 93 and Firefox ESR 91.2

Reporter
Mozilla developers
Impact
high
Description

Mozilla developers and community members Kevin Brosnan, Mihai Alexandru Michis, and Christian Holler reported memory safety bugs present in Firefox 92 and Firefox ESR 91.1. 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-2021-38499: Memory safety bugs fixed in Firefox 93

Reporter
Mozilla developers and community
Impact
high
Description

Mozilla developers and community members Julien Cristau, Christian Holler reported memory safety bugs present in Firefox 92. 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