Mozilla Foundation Security Advisory 2021-47

Security Vulnerabilities fixed in Thunderbird 91.2

Announced
October 6, 2021
Impact
high
Products
Thunderbird
Fixed in
  • Thunderbird 91.2

In general, these flaws cannot be exploited through email in the Thunderbird product because scripting is disabled when reading mail, but are potentially risks in browser or browser-like contexts.

#CVE-2021-38502: Downgrade attack on SMTP STARTTLS connections

Reporter
Mattias Jacobsson
Impact
high
Description

Thunderbird ignored the configuration to require STARTTLS security for an SMTP connection. A MITM could perform a downgrade attack to intercept transmitted messages, or could take control of the authenticated session to execute SMTP commands chosen by the MITM. If an unprotected authentication method was configured, the MITM could obtain the authentication credentials, too.

References

#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 Thunderbird 91.2

Reporter
Mozilla developers
Impact
high
Description

Mozilla developers and community members Andreas Pehrson and Christian Holler reported memory safety bugs present in Thunderbird 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-2021-38501: Memory safety bugs fixed in Thunderbird 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 Thunderbird 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