Microsoft Corp. patched three vulnerabilities in the company’s Server Message Block (SMB) file-sharing protocol, including two that could make “Swiss cheese” out of enterprise networks, according to one researcher. “Expect to see a worm on this one in the very near future, [because] this is Blaster and Sasser all over again.” Those two worms, 2003’s Blaster and 2004’s Sasser, wreaked havoc worldwide as they spread to millions of Windows machines.
Of the three bugs outlined in the MS09-001 security bulletin, two were rated “critical,” the most serious ranking in Microsoft’s four-step scoring system, while the third was pegged “moderate.” The pair identified as critical are extremely dangerous because attackers can exploit them simply by sending malformed data to unpatched machines, according to the chief technology officer. “These flaws enable an attacker to send evil packets to a Microsoft computer and take any action they desire on that computer [with] no credentials required,” he said. “The only prerequisite for this attack to be successful is a connection from the attacker to the victim over the NetBIOS ports, TCP 139 or TCP 445. By default, most computers have these ports turned on. More people have blocked those ports, and more personal firewalls block them by default, but they are typically left open in a corporate network.”
Source: Computer World