The nature of intuition and conditions of its validity and how it is related to and verified against objective criteria comprise a huge topic to discuss. But just to provide you with a glimpse into the subject, intuition is a strike of truth or a truthful realization that comes neither from sensual percepts nor exercise of intellect (reasoning).
The Nature of Intuition, A Philosophical Intro
In the following I can only provide a summary description of the nature and main workings of intuition according to muslim theosophists such as al-Farabi and Mulla Sadra.
First of all, it is believed that all developments of the natural world are determined by God and His agents, the angels. Archangel Gabriel represents the full knowledge of every existing being. Through their communication with Archangel Gabriel, Divine Prophets gain ultimate knowledge about everything.
It is now believed by muslim theosophists, that even for ordinary human beings, both philosophical and intuitive knowledge emanate from Gabriel.
The idea that philosophical knowledge emanates from non-material, intellectual forms unto human soul was first proven and elaborated by the Greek Plotinus.
Later, the muslim philosopher, al-Farabi, adopted and expanded upon the theory arguing that when a philosopher arrives at a new conclusion or statement of fact after a truthful contemplation or the process of logical reasoning, he is in reailty being enlightened by what he termed as the Active (or Agent or Universal) Intellect.
He also argued that this agent corresponds to Gabriel who is also responsible for revealing Divine knowledge and commandments to the Prophets.
However, intuition in its more common application can be equated to introspection. Evidently, we make many valid statements of personal truth only by an insight into the realities of our soul or mind. For example, every random idea that strikes our mind (that can be expressed as "I am thinking about this [random idea]") is sensed through a direct, immediate internal realization. In other words, in such examples, we simply know what is going in our mind or heart without any recurse to any form of logical reasoning or empirical proof. These forms of intuition that are regarded as the most primitive and basic principles in classical philosophy of mind and epistemology, form the self-evident principles of logic which in turn serve as the foundation of First Philosophy from which other forms of knowledge are inferred by deductive and inductive reasoning.
The subjects of common forms of intuition are dreams, feelings, emotions, abstract concepts and self-evident principles all sensed and confirmed without the need to exercise of logical thinking.
All Intuitions Are Infallible?
The real problematic subject of intuition is however dreams which I think is also the core of your question as all other forms of common intuition that I mentioned just above are confirmed with definite certainty, i.e. emotions, abstract concepts and self-evident principles.
For example when you feel pain, anger or love as emotions you can't whatsoever doubt that you are sensing them and that they are real---that is in contrast to your sensual percepts as you can't be totally sure whether you really heard the sound you think your heard, saw the thing you thought you saw, etc without certifying verification(s). Same goes for self-evident principles that humans naturally discover as absolute fundamental laws of reality (e.g. non-contradiction, identity, etc) during early months of their life as infants that are confirmed with full certainty. These types of intuitive perception are thus infallible from any error.
But despite the fact that dreams are also doubtlessly sensed and confirmed through intuition, it is their implied interpretative meaning, if any, that is hard to verify.
Dreams and extraordinary visions, according to theosophists, can reflect either Divinely or angelically revealed truths or just random thoughts caused by physiological or psychological conditions or daily life experiences. The later group of dreams and visions which are actually the most common have evidently no basis in truth.
However actual verification of the truthfulness of the former type (i.e. truthful dreams or visions that are believed to be revealed by God or Angels) is a challenging job mainly for two reasons:
only a learned theosophist with a logically validated philosophical knowledge of the universe on one hand and a correct comprehensive understanding of the previous divinely revealed truths (i.e. doctrines of Divine religions revealed to infallible saints or prophets) can examine truthfulness of new claims of intuitive truth by the fallible men. These claims should not conflict with beliefs already established by revelations to infallible saints, and also should not contradict the logically established philosophical statements about the universe.
the most challenging difficulty associated with dream or vision verification/interpretation, is the fact that many truthful visions or dreams are experienced in metaphorical, symbolic forms. For example according to Islamic traditions, Prophet Muhammad once had a dream seeing baboons climbing his throne and was wondering about its interpretation. But soon later, he received a second more clear revelation that explained the actual meaning of what was only vaguely revealed to him during the dream: that after his death his most wicked sworn enemies (Ummayads) will take over his throne. This second clarifying Divine revelation finds mention in the Quran. The merit of the latter revelation was that he actually saw Gabriel explaining to him what the first dream meant while the former was shrouded in a metaphor.
Therefore the question of infallibility of such dreams is more about a technical, interpretive difficulty, as they are various ways to express one statement of truth through symbolic/metaphorical expressions. Also often times it is practically impossible to even verify whether a dream or a vision has any truthful implication or is just a bunch of crazy meaningless thoughts caused by random physiological or psychological conditions. That's why there are few real dream-interpreters.