USN-4930-1: Samba vulnerability

Releases

• Ubuntu 21.04
• Ubuntu 20.10
• Ubuntu 20.04 LTS
• Ubuntu 18.04 ESM
• Ubuntu 16.04 ESM

Packages

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

Details

Peter Eriksson discovered that Samba incorrectly handled certain negative
idmap cache entries. This issue could result in certain users gaining
unauthorized access to files, contrary to expected behaviour.

Update instructions

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

Ubuntu 21.04

• samba - 2:4.13.3+dfsg-1ubuntu2.1

Ubuntu 20.10

• samba - 2:4.12.5+dfsg-3ubuntu4.3

Ubuntu 20.04

• samba - 2:4.11.6+dfsg-0ubuntu1.8

Ubuntu 18.04

• samba - 2:4.7.6+dfsg~ubuntu-0ubuntu2.23

Ubuntu 16.04

• samba - 2:4.3.11+dfsg-0ubuntu0.16.04.34

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

References

• CVE-2021-20254

Related notices

• USN-4931-1: libsmbsharemodes-dev, samba-libs, samba-common-bin, smbclient, libwbclient0, python-samba, libpam-smbpass, winbind, registry-tools, libparse-pidl-perl, samba-dev, samba-vfs-modules, libsmbclient, samba-dsdb-modules, libwbclient-dev, libsmbsharemodes0, samba-common, samba-doc, libnss-winbind, libpam-winbind, samba-testsuite, libsmbclient-dev, samba