CVE-2020-12420 Use after free in Firefox
A race condition during STUN server connection causes a use-after-free, potentially allowing attackers to execute arbitrary code or crash the browser.
- 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-2020-12420?
CVE-2020-12420 is a high-severity use after free vulnerability in Canonical Ubuntu Linux, published on 9 Jul 2020. 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
When trying to connect to a STUN server, a race condition could have caused a use-after-free of a pointer, leading to memory corruption and a potentially exploitable crash. This vulnerability affects Firefox ESR < 68.10, Firefox < 78, and Thunderbird < 68.10.0.
Which versions are affected by CVE-2020-12420?
It affects 5 products.
Products include Canonical Ubuntu Linux, Mozilla Firefox, Mozilla Firefox Esr, Mozilla Thunderbird, Opensuse Leap.
How do I fix CVE-2020-12420?
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-2020-12420 being exploited?
There is no known exploitation of CVE-2020-12420 in the wild and no public exploit code.
Other vulnerabilities in Canonical Ubuntu Linux
Sources
Also known as DEBIAN-CVE-2020-12420, GHSA-g65h-q52v-q3xv, UBUNTU-CVE-2020-12420.