Windows NT security is getting worse. That's the assessment of top security experts following their discovery last week of yet another security vulnerability in Windows NT that leaves the operating system wide open to password and denial-of-service attacks on virtual private networks.
At least 12 major security breaches have been found so far this year by so-called "white-hat" hackers - people who look for flaws to expose rather than exploit - and posted on independent Windows NT security World Wide Web pages.
The latest glitch cropped up in Microsoft's implementation of the Point-to-Point-Tunnelling Protocol (PPTP), which the company includes free as part of the Remote Access Service in Windows NT 4.0, said Bruce Schneier, head cryptographer at Counterpane Systems, a US security consulting firm.
"We found several major security flaws in Microsoft's PPTP that will let hackers sniff passwords across the network, break the encryption scheme, read confidential data and mount denial-of-service attacks against PPTP servers," Schneier said. "The security problems in NT will only worsen as Microsoft increases the complexity of the operating system."
Microsoft's version of PPTP - not the actual protocol itself - is so severe that "there's no real way to fix it," added Peter Mudge, director of L0pht group Seven White-hat Hackers, based in the US.
Schneier and Mudge advise businesses to use the IPSec protocol standard instead of Microsoft's PPTP. IPSec was designed by the Internet Engineering Task Force, a standards group.
Microsoft has acknowledged the flaw in its version of the PPTP protocol. Microsoft said it is working on a fix that it expects to post "soon". But Microsoft officials denied Schneier's and Mudge's assertions that its PPTP protocol couldn't be fixed.
NT's popularity has made it the target of an increasing number of hacks.
"Hacking NT has clearly become a favourite blood sport among the hacker underground," observed Mark Fabro, director of the advanced security assessment division of Secure Computing.
NT can be "a secure operating system", but only if network administrators are well versed on current security issues and have updated their NT servers with the latest fixes and patches, he said.