It should be possible to see which projects a user has access to in JIRA

Problem Definition

Finding out the current access that a user has is an important security feature in user management

Suggested Solution

An overview of all projects to which a user has access (with possible drill-down to determine the exact access rights for that project), would help immensely, and make the overall security process easier to control.

Workaround

Use the permission helper but you have to choose an issue per project and you can check one project at the time, having many projects this can take quite some time.