Did Russian Hackers Crash Skype?
An anonymous reader sends us to the www.xakep.ru forum where a poster claims that the worldwide Skype crash was caused by Russian hackers (in Russian). The claim is that they found a local buffer overflow vulnerability caused by sending a long string to the Skype authorization server. You can try Google's beta Russian-to-English translation, but the interesting part is the exploit code, and that's more readable in the original. The Washington Post reports that Skype has denied this rumor.
strncpy
"When life gives you lemons, don't make lemonade. Make life take the lemons back!" -- Cave Johnson
Skype's login servers usually don't carry much load compared to the mass of traffic routed directly between all nodes via P2P. My guess is they just got overrun because they were not prepared for the worst case: ALL clients trying to connect AT THE SAME TIME to their master. I bet Slashdot wouldn't be prepared for all of its users connecting at the same time, either. But it needs not to. It is never going to happen (why should it? - well how about December 1st, 1AM UTC everybody?). With Skype it's different. They should have been prepared for the case, that whenever their network would be down for whatever reason all clients would try to connect concurrently! Obviously they weren't prepared. If you watched the aftermath closely you could see that they started filtering by IP on day two. Only a certain number of clients were allowed to connect per IP range. They probably hired super expensive DoS emergency contractors to get this back up. A hack is still possible, but I rather guess that it brought the network down, but did not keep it from coming back up. That was Skype's own fault.
It probably has more to do with Skype retooling for eavesdropping requirements under the new wiretap law. Skype handles a lot of international traffic, encrypted and often in a P2P fashion, so a major change is necessary in order to comply.
From what little I know about Skype, the network can cause both parties in a Skype-Skype call to route through a third party, a supernode (this is done to defeat firewall complications). So perhaps they would be able to start routing all USA-international traffic through in-house supernodes where the stream could be tapped. (Anyone want to correct me? Clarify?)