Researchers uncover major IP flawOctober 1, 2008 – 5:37 AM
Researchers at Finnish security firm Outpost 24 claim to have discovered a flaw in the Internet Protocol that can disrupt any computer or server.
After keeping the flaw quiet for years, the researchers hope that going public will help accelerate the creation of a solution.
The flaw allows attackers to cripple computers and servers by sending a few specially formed TCP/IP packets. The result can be compared to a denial of service attack, in which networks are flooded with traffic. But in the case of the newly revealed flaw, only a minimum of traffic is required. “We’re talking 10 packets per second to take down one service,” Jack Lewis, a senior researcher with Outpost24.
Researchers at Fox-IT, a Dutch security firm, confirm the issue. “Based on the available information, this vulnerability may be a serious problem for system availability,” observed Erwin Paternotte, a researcher with Fox-IT. “If the technical details are publicly disclosed, performing a denial-of-service attack will become relatively trivial.”
The problem surfaced during a test scan of 67 million Internet hosts. The researchers were alerted when a test caused some hosts to become unresponsive. Further investigation led to an issue in the TCP/IP stack. After a connection is successfully made, important system resources are at the attacker’s disposal.
Each operating system is affected by the flaw, although different systems respond in different ways. “Each operating system does behave differently, of course. You might notice with OS X that a couple attacks that don’t seem to bother too much completely devastate Windows XP and the other way around,” said Lewis.
The researchers have crafted proof-of-concept code that demonstrates the issues. They claim that they hadn’t seen a single implementation of TCP/IP that wasn’t vulnerable. Systems remain unresponsive after an attack. “After the attack is over, the system never seems to recover until it is rebooted,” said Robert Lee, Outpost24’s chief security officer.