Following last week’s major Christmas Day issues – which saw random user’s private details visible for a short time – Valve have now issued an official statement as to the cause behind Steam’s most recent hiccup. Posting via Steam’s news section, Valve have claimed this was due to a recent Denial of Service attack which affected both Steam itself and, as the company explain, the ‘web caching partner’ they use in conjunction.
‘Between 11:50 PST and 13:20 PST store page requests for about 34k users, which contained sensitive personal information, may have been returned and seen by other users. The content of these requests varied by page, but some pages included a Steam user’s billing address, the last four digits of their Steam Guard phone number, their purchase history, the last two digits of their credit card number, and/or their email address.’
A likely consequence of the recent Winter Sales, Steam’s web traffic increased by 2000%, the company explain, yet they have reiterated only a fraction of financial details were ever visible.
‘These cached requests did not include full credit card numbers, user passwords, or enough data to allow logging in as or completing a transaction as another user. Once this error was identified, the Steam Store was shut down and a new caching configuration was deployed. The Steam Store remained down until we had reviewed all caching configurations, and we received confirmation that the latest configurations had been deployed to all partner servers and that all cached data on edge servers had been purged.
We will continue to work with our web caching partner to identify affected users and to improve the process used to set caching rules going forward. We apologize to everyone whose personal information was exposed by this error, and for interruption of Steam Store service.’
Valve explain that an incorrect caching of information – as a result of a second DoS attack on the service – may have unintentionally allowed specific users to view one another’s details, though they go on to reassure readers that they are now in the process of identifying and contacting those they believe were affected by said attack.