Sybase system procedures are stored in the database sybsystemprocs. When a user in any database executes any stored procedure, Adaptive Server first looks for that procedure in the user’s current database. If there is no procedure there with that name, Adaptive Server looks for it in sybsystemprocs. If there is no procedure in sybsystemprocs by that name, Adaptive Server looks for the procedure in master.
If the procedure modifies system tables (for example, sp_adduser modifies the sysusers table), the changes are made in the database from which the procedure was executed.
To change the default permissions on system procedures, you must modify those permissions in sybsystemprocs.
Any time you make changes to sybsystemprocs, you should back up the database.