CVE-2021-38496 Use after free in Firefox
A use-after-free flaw in MessageTask operations allows attackers to cause memory corruption, leading to crashes or potential code execution in Firefox and Thunderbird.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- Available
What is CVE-2021-38496?
CVE-2021-38496 is a high-severity use after free vulnerability in Debian Debian Linux, published on 3 Nov 2021. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Official 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. This vulnerability affects Thunderbird < 78.15, Thunderbird < 91.2, Firefox ESR < 91.2, Firefox ESR < 78.15, and Firefox < 93.
Weakness: CWE-416
Which versions are affected by CVE-2021-38496?
It affects 4 products.
Products include Debian Debian Linux, Mozilla Firefox, Mozilla Firefox Esr, Mozilla Thunderbird.
How do I fix CVE-2021-38496?
Upgrade to a fixed version.
Upgrade to the fixed version. These bugs are found with fuzzing and sanitisers and avoided by memory-safe languages. More about Use after free.
Is CVE-2021-38496 being exploited?
There is no known exploitation of CVE-2021-38496 in the wild and no public exploit code.
Other vulnerabilities in Debian Debian Linux
Sources
Also known as DEBIAN-CVE-2021-38496, GHSA-3rfx-pjp7-cvfp, UBUNTU-CVE-2021-38496.