Is it bad practice to use and set global variables in promise

It's common that some information, returned from a certain promise, need to be used in a later step. One example is db connection:

database.connect()
    .then(dbConnection => runStepOne(dbConnection))
    // runStepOne is async and needs db
    .then(returnValOfStepOne => runStepTwo(returnValOfStepOne, dbConnection))
    // runStepTwo needs both stepOne's return value and db - this is totally reasonable
    // but dbConnection is not available here anymore

To circumvent this, I usually do:

var db;
database.connect()
    .then(dbConnection => db = dbConnection)
    .then(() => runStepOne(db))
    // access global
    .then(returnValOfStepOne => runStepTwo(returnValOfStepOne, db))
    // access global again

Question is, is this right or wrong? Are there any better patterns for this problem?