The code sample provided involves LDAP (Lightweight Directory Access Protocol) query syntax, not SQL or command injection syntax. LDAP injections occur when user-supplied inputs are not properly sanitized before being incorporated into LDAP queries. The given code demonstrates a potential LDAP injection point, where an attacker might manipulate the (userid=*) part to execute unauthorized queries or access unauthorized information within the LDAP directory. Boolean and Blind SQL injections, as well as Command injections, do not apply to LDAP query syntax.