CVE-2023-52927 netfilter: allow exp not to be removed in nf_ct_find_expectation
A use-after-free vulnerability in the Linux kernel netfilter subsystem allows attackers to potentially execute code or cause a denial of service.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2023-52927?
CVE-2023-52927 is a high-severity use after free vulnerability in Debian Debian Linux, published on 14 Mar 2025. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
netfilter: allow exp not to be removed in nf_ct_find_expectation
Currently nf_conntrack_in() calling nf_ct_find_expectation() will remove the exp from the hash table. However, in some scenario, we expect the exp not to be removed when the created ct will not be confirmed, like in OVS and TC conntrack in the following patches.
This patch allows exp not to be removed by setting IPS_CONFIRMED in the status of the tmpl.
Weakness: CWE-416
Which versions are affected by CVE-2023-52927?
It affects 2 products.
Products include Debian Debian Linux, Linux kernel.
How do I fix CVE-2023-52927?
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-2023-52927 being exploited?
There is no known exploitation of CVE-2023-52927 in the wild and no public exploit code.
Public exploit code: 2 proofs of concept on GitHub.
Other vulnerabilities in Debian Debian Linux
Sources
Also known as BELL-CVE-2023-52927, DEBIAN-CVE-2023-52927, GHSA-6952-99fq-g3mw, ROOT-OS-DEBIAN-11-CVE-2023-52927, UBUNTU-CVE-2023-52927.