This vulnerability in sssd allows a local unprivileged attacker to trigger a denial of service in the NSS responder by sending a crafted request with a zero-length body to its local UNIX socket. The NSS responder may become unstable or terminate, impacting system availability. The flaw is due to an integer underflow (wraparound) condition. The attack requires local access and does not affect confidentiality or integrity. The vendor rates this issue as moderate severity with a CVSS 3.1 score of 4.0 (AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L).

The impact is limited to availability, causing the NSS responder service to crash or become unstable, which may disrupt local user and group resolution services. There is no impact on confidentiality or integrity, and no remote exploitation is possible. The vulnerability requires local access and does not allow privilege escalation or code execution.

Red Hat advises restricting access to the NSS responder UNIX socket or disabling the NSS responder if it is not required. To disable, remove 'nss' from the 'services' line in the /etc/sssd/sssd.conf file and restart the sssd service. Disabling the NSS responder may affect local user and group resolution. No official patch is explicitly stated in the advisory; therefore, patch status is not yet confirmed — check the vendor advisory for current remediation guidance.