CVE-2023-41913

Publication date 20 November 2023

Last updated 26 August 2025

Ubuntu priority

Cvss 3 Severity Score

Description

strongSwan before 5.9.12 has a buffer overflow and possible unauthenticated remote code execution via a DH public value that exceeds the internal buffer in charon-tkm's DH proxy. The earliest affected version is 5.3.0. An attack can occur via a crafted IKE_SA_INIT message.

Read the notes from the security team

Status

Show unmaintained releases

Package	Ubuntu Release	Status
strongswan	23.10 mantic	Fixed 5.9.11-1ubuntu1.1
	23.04 lunar	Fixed 5.9.8-3ubuntu4.1
	22.04 LTS jammy	Fixed 5.9.5-2ubuntu2.2
	20.04 LTS focal	Fixed 5.8.2-1ubuntu3.6
	18.04 LTS bionic	Fixed 5.6.2-1ubuntu2.9+esm1
	16.04 LTS xenial	Fixed 5.3.5-1ubuntu3.8+esm4
	14.04 LTS trusty	Not affected

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Notes

mdeslaur

After the USN was published, it was discovered that the Ubuntu packages aren't built with --enable-tkm, so the vulnerable code isn't built at all. If this is enabled in the future, the jammy and earlier patches (inlcuding esm) need to be fixed to use diffie_hellman_verify_value() instead of key_exchange_verify_pubkey() for those older versions. Marking remaining releases as "not-affected"

Severity score breakdown

Parameter	Value
Base score	9.8 · Critical
Attack vector	Network
Attack complexity	Low
Privileges required	None
User interaction	None
Scope	Unchanged
Confidentiality	High
Integrity impact	High
Availability impact	High
Vector	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H