Sssd: local oob read in nss service request parsers (`sss_nss_protocol_parse_svc_name` / `sss_nss_protocol_parse_svc_port`)

A flaw was found in the sssd NSS responder. This input validation vulnerability allows a local attacker, by sending specially crafted service lookup requests to the NSS responder's UNIX socket, to cause an out-of-bounds read. This out-of-bounds read may lead to a denial of service (DoS) by crashing the NSS responder process. While unprivileged local clients can typically reach the socket, there is no evidence of privilege escalation or reliable data disclosure.