The Ubuntu Forums website has been broken into and users' credentials stolen en masse, according to a notice from Canonical, the owner, at the site.
Canonical said while the passwords of users were not stored as plain text, it was advisable for anyone using the same username-password combination elsewhere to change them as soon as possible.
The company said other services it hosts, including Ubuntu One and Launchpad, had not been affected by the break-in.
The website break-in was reported on 20 July when a defacement was noticed.
It is not clear at this point whether the break-in was achieved through a vulnerability in the software being used to host the forum or through a vulnerability in the operating system on which the forum software was running.
HOW TO OFFER 4G TO YOUR CUSTOMERS
Download an information pack to learn more about how you can offer competitive 4G plans to your customers.
> everything you need to operate your own 4G telco
> support for you and your customers
> billing, back-end and full compliance.