CVE-2020-36694 Use after free in n/a
A use-after-free in the Linux kernel netfilter allows local attackers with CAP_NET_ADMIN to execute code or escalate privileges.
- 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-2020-36694?
CVE-2020-36694 is a medium-severity use after free vulnerability in Linux kernel, published on 21 May 2023. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
An issue was discovered in netfilter in the Linux kernel before 5.10. There can be a use-after-free in the packet processing context, because the per-CPU sequence count is mishandled during concurrent iptables rules replacement. This could be exploited with the CAP_NET_ADMIN capability in an unprivileged namespace. NOTE: cc00bca was reverted in 5.12.
Weakness: CWE-416
Which versions are affected by CVE-2020-36694?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2020-36694?
Apply the vendor's patch.
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-2020-36694 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2020-36694 exists.
Other vulnerabilities in Linux kernel
Sources
Also known as DEBIAN-CVE-2020-36694, GHSA-7prr-xcc8-8wpv, ROOT-OS-DEBIAN-11-CVE-2020-36694, ROOT-OS-DEBIAN-12-CVE-2020-36694, ROOT-OS-DEBIAN-13-CVE-2020-36694, UBUNTU-CVE-2020-36694.