CVE-2023-3777 Use-after-free in Linux kernel's netfilter: nf_tables component

What is CVE-2023-3777?

CVE-2023-3777 is a high-severity use after free vulnerability in Canonical Ubuntu Linux, published on 6 Sep 2023. It can only be exploited from the same machine or local network, with no action from the victim.

Official description

A use-after-free vulnerability in the Linux kernel's netfilter: nf_tables component can be exploited to achieve local privilege escalation.

When nf_tables_delrule() is flushing table rules, it is not checked whether the chain is bound and the chain's owner rule can also release the objects in certain circumstances.

We recommend upgrading past commit 6eaf41e87a223ae6f8e7a28d6e78384ad7e407f8.

Weakness: CWE-416

Which versions are affected by CVE-2023-3777?

It affects 3 products.

Products include Canonical Ubuntu Linux, Debian Debian Linux, Linux kernel.

How do I fix CVE-2023-3777?

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-2023-3777 being exploited?

There is no known exploitation of CVE-2023-3777 in the wild and no public exploit code.

Other vulnerabilities in Canonical Ubuntu Linux

• CVE-2020-11651 SaltStack Salt Authentication Bypass Exploited Critical 9.8
• CVE-2020-7247 OpenSMTPD Remote Code Execution Exploited Critical 9.8
• CVE-2019-16928 Exim Out-of-bounds Write Exploited Critical 9.8
• CVE-2018-6789 Exim Buffer Overflow Exploited Critical 9.8
• CVE-2015-2590 Oracle Java SE and Java SE Embedded Remote Code Execution Exploited Critical 9.8

All Canonical Ubuntu Linux vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as DEBIAN-CVE-2023-3777, GHSA-3v7f-rjgx-9grq, SUSE-SU-2023:4781-1, UBUNTU-CVE-2023-3777.