A flaw was found in sssd, specifically within the PAM (Pluggable Authentication Modules) responder's protocol v1 parser, pam_parse_in_data(). A local client with access to the PAM responder's UNIX socket can exploit this by negotiating protocol v1 and sending an empty or truncated PAM request body. This can trigger an out-of-bounds read, potentially causing the PAM responder to terminate or restart, leading to a local denial of service.
Restrict local access to the PAM responder UNIX socket, typically located at /var/lib/sss/pipes/pam, to only trusted users and processes. This can be achieved by adjusting file system permissions on the socket file.