========================================================================== Ubuntu Security Notice USN-5067-1 September 08, 2021 sssd vulnerabilities ========================================================================== A security issue affects these releases of Ubuntu and its derivatives: - Ubuntu 21.04 - Ubuntu 20.04 LTS - Ubuntu 18.04 LTS Summary: Several security issues were fixed in sssd. Software Description: - 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 LTS: sssd 2.2.3-3ubuntu0.7 Ubuntu 18.04 LTS: sssd 1.16.1-1ubuntu1.8 In general, a standard system update will make all the necessary changes. References: https://ubuntu.com/security/notices/USN-5067-1 CVE-2018-10852, CVE-2018-16838, CVE-2019-3811, CVE-2021-3621 Package Information: https://launchpad.net/ubuntu/+source/sssd/2.4.0-1ubuntu6.1 https://launchpad.net/ubuntu/+source/sssd/2.2.3-3ubuntu0.7 https://launchpad.net/ubuntu/+source/sssd/1.16.1-1ubuntu1.8