CVE-2023-23009 Denial of service in n/a

Medium 6.5 Published 21 Feb 2023 Updated 17 Mar 2025

Remote attackers can cause a denial of service in Libreswan by sending crafted TS payloads, leading to daemon restarts.

Exploited in the wild: Not known
Login needed: Any signed-in user
Attackable: Over the internet
Victim action needed: Not needed
Fix: Available

What is CVE-2023-23009?

CVE-2023-23009 is a medium-severity denial of service vulnerability in Debian Debian Linux, published on 21 Feb 2023. Any signed-in user can exploit it over the network, with no action from the victim.

Official description

Libreswan 4.9 allows remote attackers to cause a denial of service (assert failure and daemon restart) via crafted TS payload with an incorrect selector length.

Weakness: CWE-400

Which versions are affected by CVE-2023-23009?

It affects 2 products.

Linux distribution packages (8)

`libreswan` AlmaLinux:8	All versions	`4.9-2.el8_8.2`
`libreswan` AlmaLinux:9	All versions	`4.9-2.el9_2`
`libreswan` Red Hat:enterprise_linux:8::appstream	All versions	`0:4.9-2.el8_8.2`
`libreswan-debuginfo` Red Hat:enterprise_linux:8::appstream	All versions	`0:4.9-2.el8_8.2`
`libreswan-debugsource` Red Hat:enterprise_linux:8::appstream	All versions	`0:4.9-2.el8_8.2`
`libreswan` Red Hat:enterprise_linux:9::appstream	All versions	`0:4.9-2.el9_2`
`libreswan-debuginfo` Red Hat:enterprise_linux:9::appstream	All versions	`0:4.9-2.el9_2`
`libreswan-debugsource` Red Hat:enterprise_linux:9::appstream	All versions	`0:4.9-2.el9_2`

Products include Debian Debian Linux, Libreswan Libreswan.

How do I fix CVE-2023-23009?

Upgrade to a fixed version.

Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.

Is CVE-2023-23009 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2023-23009 exists.

All Debian Debian Linux vulnerabilities

Sources

Also known as ALSA-2023:2633, ALSA-2023:3095, DEBIAN-CVE-2023-23009, DSA-5368-1, GHSA-3gxg-hfhr-6g9x, MGASA-2023-0089 and 5 more.