USN-6425-2: Samba regression

11 October 2023

USN-6425-1 introduced a regression in Samba.

Reduce your security exposure

Ubuntu Pro provides ten-year security coverage to 25,000+ packages in Main and Universe repositories, and it is free for up to five machines.

Learn more about Ubuntu Pro

Releases

Packages

  • samba - SMB/CIFS file, print, and login server for Unix

Details

USN-6425-1 fixed vulnerabilities in Samba. Due to a build issue on Ubuntu
20.04 LTS, the update introduced regressions in macro handling and
possibly other functionality.

This update fixes the problem. We apologize for the inconvenience.

Original advisory details:

Sri Nagasubramanian discovered that the Samba acl_xattr VFS module
incorrectly handled read-only files. When Samba is configured to ignore
system ACLs, a remote attacker could possibly use this issue to truncate
read-only files. (CVE-2023-4091)

Andrew Bartlett discovered that Samba incorrectly handled the DirSync
control. A remote attacker with an RODC DC account could possibly use this
issue to obtain all domain secrets. (CVE-2023-4154)

Andrew Bartlett discovered that Samba incorrectly handled the rpcecho
development server. A remote attacker could possibly use this issue to
cause Samba to stop responding, resulting in a denial of service.
(CVE-2023-42669)

Kirin van der Veer discovered that Samba incorrectly handled certain RPC
service listeners. A remote attacker could possibly use this issue to cause
Samba to start multiple incompatible RPC listeners, resulting in a denial
of service. This issue only affected Ubuntu 22.04 LTS, and Ubuntu 23.04.
(CVE-2023-42670)

Reduce your security exposure

Ubuntu Pro provides ten-year security coverage to 25,000+ packages in Main and Universe repositories, and it is free for up to five machines.

Learn more about Ubuntu Pro

Update instructions

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

Ubuntu 20.04

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