A flaw was found in the System Security Services Daemon (SSSD). The pam_passkey_child_read_data() function within the PAM passkey responder fails to properly handle raw bytes received from a pipe. Because the data is treated as a NUL-terminated C string without explicit termination, it results in an out-of-bounds read when processed by functions like snprintf().

A local attacker could potentially trigger this vulnerability by initiating a crafted passkey authentication request, causing the SSSD PAM responder to crash, resulting in a local Denial of Service (DoS).