CVE-2023-3567 Kernel: use after free in vcs_read in drivers/tty/vt/vc_screen.c due to race

What is CVE-2023-3567?

CVE-2023-3567 is a high-severity use after free vulnerability in Canonical Ubuntu Linux, published on 24 Jul 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 flaw was found in vcs_read in drivers/tty/vt/vc_screen.c in vc_screen in the Linux Kernel. This issue may allow an attacker with local user access to cause a system crash or leak internal kernel information.

Weakness: CWE-416

Which versions are affected by CVE-2023-3567?

It affects 3 products.

Products include Canonical Ubuntu Linux, Linux kernel, Redhat Enterprise Linux.

How do I fix CVE-2023-3567?

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-2023-3567 being exploited?

There is no known exploitation of CVE-2023-3567 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 AZL-27758, DEBIAN-CVE-2023-3567, GHSA-cgvp-6hhh-fqwh, UBUNTU-CVE-2023-3567.