vouch vs attest

vouch and attest both are verbs.

Word	Noun	Adjective	Verb	Adverb
vouch	No	No	Yes	No
attest	No	No	Yes	No

As verbs, attest is a hypernym of vouch; that is, attest is a word with a broader meaning than vouch:

Other hypernyms of vouch include bear witness, take the stand, testify.

vouch (verb)	attest (verb)
give supporting evidence	authenticate, affirm to be true, genuine, or correct, as in an official capacity
summon (a vouchee) into court to warrant or defend a title	provide evidence for; stand as proof of; show by one's behavior, attitude, or external attributes
give personal assurance; guarantee	give testimony in a court of law
give surety or assume responsibility	establish or verify the usage of