Debian Security Advisory

DSA-5015-1 samba -- security update

Date Reported:
30 Nov 2021
Affected Packages:
Security database references:
In Mitre's CVE dictionary: CVE-2020-25717.
More information:

Andrew Bartlett discovered that Samba, a SMB/CIFS file, print, and login server for Unix, may map domain users to local users in an undesired way. This could allow a user in an AD domain to potentially become root on domain members.

A new parameter min domain uid (default 1000) has been added to specify the minimum uid allowed when mapping a local account to a domain account.

Further details and workarounds can be found in the upstream advisory

For the oldstable distribution (buster), this problem has been fixed in version 2:4.9.5+dfsg-5+deb10u2. Additionally the update mitigates CVE-2020-25722. Unfortunately the changes required to fix additional CVEs affecting Samba as an AD-compatible domain controller are too invasive to be backported. Thus users using Samba as an AD-compatible domain controller are encouraged to migrate to Debian bullseye. From this point onwards AD domain controller setups are no longer supported in Debian oldstable.

We recommend that you upgrade your samba packages.

For the detailed security status of samba please refer to its security tracker page at: