CVE-2021-43528: Security Vulnerabilities fixed in Thunderbird 91.4.0

Mozilla Foundation Security Advisory 2021-54

Announced

December 7, 2021

Impact

high

Products

Thunderbird

Fixed in

• Thunderbird 91.4

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-2021-43536: URL leakage when navigating while executing asynchronous function

Reporter

Sunwoo Kim and Youngmin Kim of SNU CompSec Lab

Impact

high

Description

Under certain circumstances, asynchronous functions could have caused a navigation to fail but expose the target URL.

References

• Bug 1730120

#CVE-2021-43537: Heap buffer overflow when using structured clone

Reporter

bo13oy of Cyber Kunlun Lab

Impact

high

Description

An incorrect type conversion of sizes from 64bit to 32bit integers allowed an attacker to corrupt memory leading to a potentially exploitable crash.

References

• Bug 1738237

#CVE-2021-43538: Missing fullscreen and pointer lock notification when requesting both

Reporter

Irvan Kurniawan (@sourc7)

Impact

high

Description

By misusing a race in our notification code, an attacker could have forcefully hidden the notification for pages that had received full screen and pointer lock access, which could have been used for spoofing attacks.

References

• Bug 1739091

#CVE-2021-43539: GC rooting failure when calling wasm instance methods

Reporter

Asumu Takikawa and Ioanna Dimitriou

Impact

high

Description

Failure to correctly record the location of live pointers across wasm instance calls resulted in a GC occurring within the call not tracing those live pointers. This could have led to a use-after-free causing a potentially exploitable crash.

References

• Bug 1739683

#CVE-2021-43541: External protocol handler parameters were unescaped

Reporter

chriscla

Impact

moderate

Description

When invoking protocol handlers for external protocols, a supplied parameter URL containing spaces was not properly escaped.

References

• Bug 1696685

#CVE-2021-43542: XMLHttpRequest error codes could have leaked the existence of an external protocol handler

Reporter

Raphael Smolik

Impact

moderate

Description

Using XMLHttpRequest, an attacker could have identified installed applications by probing error messages for loading external protocols.

References

• Bug 1723281

#CVE-2021-43543: Bypass of CSP sandbox directive when embedding

Reporter

Armin Ebert

Impact

moderate

Description

Documents loaded with the CSP sandbox directive could have escaped the sandbox’s script restriction by embedding additional content.

References

• Bug 1738418

#CVE-2021-43545: Denial of Service when using the Location API in a loop

Reporter

Paul Zühlcke

Impact

low

Description

Using the Location API in a loop could have caused severe application hangs and crashes.

References

• Bug 1720926

#CVE-2021-43546: Cursor spoofing could overlay user interface when native cursor is zoomed

Reporter

Daniel Veditz

Impact

low

Description

It was possible to recreate previous cursor spoofing attacks against users with a zoomed native cursor.

References

• Bug 1737751

#CVE-2021-43528: JavaScript unexpectedly enabled for the composition area

Reporter

Pedro Batista

Impact

low

Description

Thunderbird unexpectedly enabled JavaScript in the composition area. The JavaScript execution context was limited to this area and did not receive chrome-level privileges, but could be used as a stepping stone to further an attack with other vulnerabilities.

References

• Bug 1742579

#MOZ-2021-0009: Memory safety bugs fixed in Thunderbird 91.4.0

Reporter

Mozilla developers and community

Impact

high

Description

Mozilla developers and community members Julian Hector, Randell Jesup, Gabriele Svelto, Tyson Smith, Christian Holler, and Masayuki Nakano reported memory safety bugs present in Thunderbird 91.3. 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

• Memory safety bugs fixed in Thunderbird 91.4.0