A Samba regression update has been released for Ubuntu Linux 20.04 LTS.

USN-5822-2: Samba regression

==========================================================================
Ubuntu Security Notice USN-5822-2
January 26, 2023

samba regression
==========================================================================

A security issue affects these releases of Ubuntu and its derivatives:

- Ubuntu 20.04 LTS

Summary:

USN 5822-1 introduced regressions on Ubuntu 20.04 LTS.

Software Description:
- samba: SMB/CIFS file, print, and login server for Unix

Details:

USN-5822-1 fixed vulnerabilities in Samba. The update for Ubuntu 20.04 LTS
introduced regressions in certain environments. Pending investigation of
these regressions, this update temporarily reverts the security fixes.

We apologize for the inconvenience.

Original advisory details:

It was discovered that Samba incorrectly handled the bad password count
logic. A remote attacker could possibly use this issue to bypass bad
passwords lockouts. This issue was only addressed in Ubuntu 22.10.
(CVE-2021-20251)
Evgeny Legerov discovered that Samba incorrectly handled buffers in
certain GSSAPI routines of Heimdal. A remote attacker could possibly use
this issue to cause Samba to crash, resulting in a denial of service.
(CVE-2022-3437)
Tom Tervoort discovered that Samba incorrectly used weak rc4-hmac Kerberos
keys. A remote attacker could possibly use this issue to elevate
privileges. (CVE-2022-37966, CVE-2022-37967)
It was discovered that Samba supported weak RC4/HMAC-MD5 in NetLogon Secure
Channel. A remote attacker could possibly use this issue to elevate
privileges. (CVE-2022-38023)
Greg Hudson discovered that Samba incorrectly handled PAC parsing. On
32-bit systems, a remote attacker could use this issue to escalate
privileges, or possibly execute arbitrary code. (CVE-2022-42898)
Joseph Sutton discovered that Samba could be forced to issue rc4-hmac
encrypted Kerberos tickets. A remote attacker could possibly use this issue
to escalate privileges. This issue only affected Ubuntu 20.04 LTS and
Ubuntu 22.04 LTS. (CVE-2022-45141)
WARNING: The fixes included in these updates introduce several important
behavior changes which may cause compatibility problems interacting with
systems still expecting the former behavior. Please see the following
upstream advisories for more information:
https://www.samba.org/samba/security/CVE-2022-37966.html
https://www.samba.org/samba/security/CVE-2022-37967.html
https://www.samba.org/samba/security/CVE-2022-38023.html

Update instructions:

The problem can be corrected by updating your system to the following
package versions:

Ubuntu 20.04 LTS:
samba 2:4.13.17~dfsg-0ubuntu1.20.04.5

In general, a standard system update will make all the necessary changes.

References:
https://ubuntu.com/security/notices/USN-5822-2
https://ubuntu.com/security/notices/USN-5822-1
https://launchpad.net/bugs/2003867, https://launchpad.net/bugs/2003891

Package Information:
https://launchpad.net/ubuntu/+source/samba/2:4.13.17~dfsg-0ubuntu1.20.04.5