USN-5067-1: SSSD vulnerabilities

Releases

• Ubuntu 21.04
• Ubuntu 20.04 LTS
• Ubuntu 18.04 ESM

Packages

• sssd - System Security Services Daemon

Details

Jakub Hrozek discovered that SSSD incorrectly handled file permissions. A
local attacker could possibly use this issue to read the sudo rules
available for any user. This issue only affected Ubuntu 18.04 LTS.
(CVE-2018-10852)

It was discovered that SSSD incorrectly handled Group Policy Objects. When
SSSD is configured with too strict permissions causing the GPO to not be
readable, SSSD will allow all authenticated users to login instead of being
denied, contrary to expectations. This issue only affected Ubuntu 18.04
LTS. (CVE-2018-16838)

It was discovered that SSSD incorrectly handled users with no home
directory set. When no home directory was set, SSSD would return the root
directory instead of an empty string, possibly bypassing security measures.
This issue only affected Ubuntu 18.04 LTS. (CVE-2019-3811)

Cedric Buissart discovered that SSSD incorrectly handled the sssctl
command. In certain environments, a local user could use this issue to
execute arbitrary commands and possibly escalate privileges.
(CVE-2021-3621)

Update instructions

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

Ubuntu 21.04

• sssd - 2.4.0-1ubuntu6.1

Ubuntu 20.04

• sssd - 2.2.3-3ubuntu0.7

Ubuntu 18.04

• sssd - 1.16.1-1ubuntu1.8

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

References

• CVE-2021-3621
• CVE-2018-10852
• CVE-2019-3811
• CVE-2018-16838