The library list for a job represents a security exposure, while it provides flexibility. This exposure is particularly important if you use public authority for objects and rely on library security as your primary means of protecting information. In this case, a user who gains access to a library has uncontrolled access to the information in the library.
To avoid the security risks of library lists, your applications can specify qualified names. When both the object name and the library are specified, the system does not search the library list. This prevents a potential intruder from using the library list to circumvent security.
However, other application design requirements might prevent you from using qualified names. If your applications rely on library lists, the following techniques can reduce the security exposure.