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The 8 most dangerous Windows vulnerabilities

The bugs that caused the most serious damage

Uncovering and exploiting Windows vulnerabilities has become as sport for many, and in a number of cases, even a career. We've rounded up a list of the worst Windows flaws we've endured since the introduction of Windows 98

Code Red: Deadly bug, disgusting soda

Bug identifier: MS01-033
Description: Unchecked buffer in index server Internet Server API (ISAPI) extension could enable web server compromise
Alias: The Code Red bug
Date published: June 18 2001

What happens when you send a tonne of data at a Microsoft web server? If it was the summer of 2001, well, you owned the network. At least that's what happened a little more than a month after Microsoft released this obscure-sounding patch for IIS web servers.

The nature of the bug was simple: take an IIS server, invoke a buffer overflow and commands spill into other parts of system memory. Because the commands were issued in the context of the system itself, the bug opened up for exploitation virtually all aspects of the server's operation.

And exploitation happened, all right, on a scale that hadn't been seen before.

On the afternoon of Friday July 13 2001, security engineers at eEye Digital Security received reports of a worm that was spreading rapidly through its customers' networks. Fueled by a limited edition, crimson, caffeinated, high-fructose corn syrup-based beverage, Mark Maiffret and Ryan Permeh spent a weekend reverse-engineering the worm, and alerted the world to its presence.

What the worm did was probe vulnerable IIS servers, infect them, and create 100 threads of itself, which then spread to other computers. If the date was between the 20th of the month and the end of the month, it would attempt to spew data at www.whitehouse.gov. Permeh and Maiffret estimated that the worm could infect approximately 500,000 unique IP addresses per day.

Upshot: Code Red really drove home the importance of patching bugs soon after Microsoft released the patch, because the patches themselves give malware authors clues to exactly where they should look for new vulnerabilities.

NEXT PAGE: The fastest infection ever

  1. These bugs caused serious damage
  2. Total server control with a single URL
  3. The Code Red bug
  4. The fastest infection ever
  5. The Blaster Worm bug
  6. The sassy bug with a lot of spunk
  7. Drive-by downloads
  8. The component that keeps on giving (headaches)

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