CVE-2020-25632 Use after free in grub2
A use-after-free in GRUB2 allows attackers to execute arbitrary code or bypass Secure Boot protections by unloading dependent modules.
- Exploited in the wild
- Not known
- Login needed
- An administrator
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2020-25632?
CVE-2020-25632 is a high-severity use after free vulnerability in Fedoraproject Fedora, published on 3 Mar 2021. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
A flaw was found in grub2 in versions prior to 2.06. The rmmod implementation allows the unloading of a module used as a dependency without checking if any other dependent module is still loaded leading to a use-after-free scenario. This could allow arbitrary code to be executed or a bypass of Secure Boot protections. The highest threat from this vulnerability is to data confidentiality and integrity as well as system availability.
Weakness: CWE-416
Which versions are affected by CVE-2020-25632?
It affects 8 products.
Products include Fedoraproject Fedora, Gnu Grub2, Netapp Ontap Select Deploy Administration Utility, Redhat Enterprise Linux, Redhat Enterprise Linux Server Aus, Redhat Enterprise Linux Server Eus and 2 more.
How do I fix CVE-2020-25632?
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-2020-25632 being exploited?
There is no known exploitation of CVE-2020-25632 in the wild and no public exploit code.
Public exploit code: 1 proofs of concept on GitHub.
Other vulnerabilities in Fedoraproject Fedora
Sources
Also known as ALPINE-CVE-2020-25632, AZL-6461, DEBIAN-CVE-2020-25632, GHSA-r6r2-gvcm-979j, UBUNTU-CVE-2020-25632.