Buddhist (Theravada) cure for "Insecurity"? While the Pali scriptures address (or at least reference) a number of specific sufferings that a human being can be subject to (Jealousy, Anger, Fear, etc.), do any of the teachings deal with the specific suffering of Insecurity (and how to overcome it)?  Meaning a lack of self-confidence, usually caused by the mind making itself subject to fears and illusions that creep in and which it lacks the strength to banish or prevent in the first place.
1.One of the ways to deal with anxiety,insecurity or lack of self confidence is by developing Sila (Morality,Integrity,Virtue,Ethics).

"Five blessings, householders, accrue to the righteous person through his practice of virtue: great increase of wealth through his diligence; a favorable reputation; a confident deportment, without timidity, in every society, be it that of nobles, brahmans, householders, or ascetics; a serene death; and, at the breaking up of the body after death, rebirth in a happy state, in a heavenly world."
— DN 16*

2.Anxiety comes from fear and fear comes from aversion,a way to counter act aversion is by practicing metta bhavana (to yourself First,make sure you spend a lot of time on yourself,lack of self confidence masks self hatred).

3.Counteract Fear by developing one of the five spiritual faculties,Faith.Take refuge in the Triple Gem,Take refuge in the Present Moment.Embrace the present moment.Anxious or not.Don't fight it or get upset that you got anxious.This just makes it worse.Just note it.Anxiety.Be present for it.Hold it in Awareness and compassion.Yes you might feel worse or uncomfortable but that's okay.You can note.Uncomfortable.No matter what arises due to insecurity to anxiety you can always Note.Which means there is something bigger than anxiety and that is Mindfulness.And soo you will see it changes.So have faith in the Buddha's teaching,put it to practice and see for yourself.