CVE-2021-23997 Use after free in Firefox
A use-after-free in the font cache allows attackers to execute arbitrary code via crafted web content, requiring users to update Firefox.
- 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-2021-23997?
CVE-2021-23997 is a high-severity use after free vulnerability in Mozilla Firefox, published on 24 Jun 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
Due to unexpected data type conversions, a use-after-free could have occurred when interacting with the font cache. We presume that with enough effort this could have been exploited to run arbitrary code. This vulnerability affects Firefox < 88.
Weakness: CWE-681
Which versions are affected by CVE-2021-23997?
It affects 1 product.
Products include Mozilla Firefox.
How do I fix CVE-2021-23997?
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-2021-23997 being exploited?
There is no known exploitation of CVE-2021-23997 in the wild and no public exploit code.
Other vulnerabilities in Mozilla Firefox
Sources
Also known as GHSA-v254-2gqm-j372, UBUNTU-CVE-2021-23997.