Directory traversal exploit

No, us neither. But it doesn't sound good.

Concept Business Systems have identified a critical flaw in the HMRC website, said elsewhere to be the equivalent to leaving open the front door to your house and providing a note of where your valuables are kept.  Hat tip: Ken Frost

And this in a week when the Revenue have finally got around to enabling their customers to file "past years" returns online. Well, in theory anyway.  One dreads to think what problems this is going to bring in practice.