The System Security Services Daemon provides a set of daemons to manage access to remote directories and authentication mechanisms. It provides an NSS and PAM interface toward the system and a pluggable back-end system to connect to multiple different account sources. It is also the basis to provide client auditing and policy services for projects such as FreeIPA. A flaw was found in the SSSD PAM responder that could allow a local attacker to crash SSSD via a carefully-crafted packet. With SSSD unresponsive, legitimate users could be denied the ability to log in to the system. Red Hat would like to thank Sebastian Krahmer for reporting this issue. This update also fixes several bugs and adds various enhancements. Documentation for these bug fixes and enhancements will be available shortly from the Technical Notes document, linked to in the References section. Users of SSSD should upgrade to these updated packages, which upgrade SSSD to upstream version 1.5.1 to correct this issue, and fix the bugs and add the enhancements noted in the Technical Notes.