Re: New Web Vulnerability - Cross-Site Tracing

>The XSS plague? The only XSS plague I know of is on Bugtraq and other

XSS (including "HTML injection" for those who make such distinctions) was the 2nd most frequently reported vulnerability last year, behind buffer overflows, based on CVE statistics. Many people still seem to think XSS is just about cookie theft. While there may not be many publicly reported exploits of XSS issues, or of web client vulnerabilities in general, it seems likely that applications will become a more attractive target to hackers as it gets more difficult to break into servers.

The fact that XSS frequently shows up in obscure applications is an indicator of how programmers are poorly trained with respect to this type of issue. (I know the state of things is bad in general, but more programmers probably know about buffer overflows than XSS). Personally, I'm glad to see the contributions made by up-and-coming vulnerability auditors who get their start by auditing easier targets. They help to demonstrate how widespread the problems are while educating the affected developers in the process, who hopefully will not make the same mistakes again.

> Code Red was a plague. Melissa was a plague.

Agreed; however, XSS worms have been theorized (see [1] for one variant), and widely deployed XSS-vulnerable applications like bulletin boards could be an unfortunate breeding ground.

• Steve

[1] http://online.securityfocus.com/archive/107/302027/2002-11-29/2002-12-05/0 Received on Thu Jan 23 19:20:56 2003