Mozilla Foundation Security Advisory 2021-36
Security Vulnerabilities fixed in Thunderbird 91
- Announced
- August 11, 2021
- Impact
- high
- Products
- Thunderbird
- Fixed in
-
- Thunderbird 91
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-2021-29986: Race condition when resolving DNS names could have led to memory corruption
- Reporter
- pahhur
- Impact
- high
Description
A suspected race condition when calling getaddrinfo led to memory corruption and a potentially exploitable crash.
Note: This issue only affected Linux operating systems. Other operating systems are unaffected.
References
#CVE-2021-29981: Live range splitting could have led to conflicting assignments in the JIT
- Reporter
- Gary Kwong
- Impact
- high
Description
An issue present in lowering/register allocation could have led to obscure but deterministic register confusion failures in JITted code that would lead to a potentially exploitable crash.
References
#CVE-2021-29988: Memory corruption as a result of incorrect style treatment
- Reporter
- Irvan Kurniawan
- Impact
- high
Description
Thunderbird incorrectly treated an inline list-item element as a block element, resulting in an out of bounds read or memory corruption, and a potentially exploitable crash.
References
#CVE-2021-29984: Incorrect instruction reordering during JIT optimization
- Reporter
- Lukas Bernhard
- Impact
- high
Description
Instruction reordering resulted in a sequence of instructions that would cause an object to be incorrectly considered during garbage collection. This led to memory corruption and a potentially exploitable crash.
References
#CVE-2021-29980: Uninitialized memory in a canvas object could have led to memory corruption
- Reporter
- Irvan Kurniawan
- Impact
- high
Description
Uninitialized memory in a canvas object could have caused an incorrect free() leading to memory corruption and a potentially exploitable crash.
References
#CVE-2021-29987: Users could have been tricked into accepting unwanted permissions on Linux
- Reporter
- Irvan Kurniawan
- Impact
- moderate
Description
After requesting multiple permissions, and closing the first permission panel, subsequent permission panels will be displayed in a different position but still record a click in the default location, making it possible to trick a user into accepting a permission they did not want to.
This bug only affects Thunderbird on Linux. Other operating systems are unaffected.
References
#CVE-2021-29985: Use-after-free media channels
- Reporter
- Marcin 'Icewall' Noga of Cisco Talos
- Impact
- moderate
Description
A use-after-free vulnerability in media channels could have led to memory corruption and a potentially exploitable crash.
References
#CVE-2021-29982: Single bit data leak due to incorrect JIT optimization and type confusion
- Reporter
- Lukas Bernhard
- Impact
- low
Description
Due to incorrect JIT optimization, we incorrectly interpreted data from the wrong type of object, resulting in the potential leak of a single bit of memory.
References
#CVE-2021-29989: Memory safety bugs fixed in Thunderbird 91
- Reporter
- Mozilla developers
- Impact
- high
Description
Mozilla developers Kershaw Chang, Philipp, Chris Peterson, Sebastian Hengst, Christoph Kerschbaumer, Olli Pettay, Sandor Molnar, and Simon Giesecke reported memory safety bugs present in versions of Thunderbird prior to 91. 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.