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Ubuntu Security Notice USN-5936-1
March 08, 2023

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

- Ubuntu 20.04 LTS

Summary:

Several security issues were fixed in Samba.

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

Details:

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: This update upgrades the version of Samba to 4.15.13. Please see
the upstream release notes for important changes in the new version:

https://www.samba.org/samba/history/samba-4.15.0.html

In addition, the security fixes included in this new version 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                           2:4.15.13+dfsg-0ubuntu0.20.04.1

This update uses a new upstream release, which includes additional bug
fixes. In general, a standard system update will make all the necessary
changes.

References:
   https://ubuntu.com/security/notices/USN-5936-1
   CVE-2022-3437, CVE-2022-37966, CVE-2022-37967, CVE-2022-38023,
   CVE-2022-42898, CVE-2022-45141

Package Information:
   https://launchpad.net/ubuntu/+source/samba/2:4.15.13+dfsg-0ubuntu0.20.04.1