Guninski's terse "high risk" advisory circulating on the Net this morning warned people using Microsoft's recently released Internet Explorer 5.5 of a security hole that could let a hacker enter their computers and tinker with files.
An intruder "could not only read files but write and execute programs on a person's computer," said Elias Levy, a SecurityFocus.com analyst and moderator of Bugtraq, where the advisory was posted. "This hole allows someone to reach into the whole computer."
The problem lies with the complexity of two subsystems. Guninski found the latest hole by running Microsoft's ActiveX technology, which manages the sending and receiving of files. Combined with Java, the technologies allow a hacker to gain access to a victim's computer, which wouldn't be possible if the systems were run independently.
A Microsoft representative said that the company's Security Response Center is investigating the vulnerability. The center, which just today announced it has hired former SecurityFocus director Eric Schultze, has received about 5,000 bug notifications since the beginning of the year. Of those, only 400 required full investigations, resulting in 70 security patches so far.
Before issuing a report, Guninski usually gives the targeted company 24 hours to fix the problem.
"That's not enough time," the Microsoft representative said. "Our biggest concern is that in a worst case scenario, it puts the customer at risk. The information is out there, and the bad guys can get their hands on it. In the best situation, it's unnecessarily spinning people up."
Levy has urged a solution to the browser troubles that go beyond providing patches.
"This is a good opportunity to focus on what can really be done to stop the never-ending flow of bugs," he wrote in an email posting. "It is obvious that the current approach of releasing code and patching it when a bug is found is not working. The security technology in consumer operating systems is woefully inadequate for the Internet age."
Last week, Guninski found that hackers could break into a victim's computer records--including cookies, or digital tags that reveal valuable information about people--using Microsoft's ActiveX technology. Microsoft previously has investigated a security vulnerability in its Internet Explorer browser that threatened to give attackers free rein in reading known files on targeted computers.