Web Server vulnerability reaches all time high

[InfoSec News <isn () c4i org>]

http://www.theregister.co.uk/content/55/26049.html

By John Leyden
Posted: 04/07/2002 at 16:22 GMT

The Web is more vulnerable to attack now than at any time previously.

That's the stark conclusion of Netcraft's latest monthly survey of Web
servers, which expresses concerns over the emergence of serious
vulnerabilities in both Microsoft's IIS and Apache Web servers over
the last month.

These vulnerabilities create a situation where a majority of Internet
sites are likely to be accessible to remote exploit, Netcraft, which
is normally associated with alarmist predictions, believes.

On June 11, Microsoft released a trio of advisories, the most serious
of which referred to a HTR buffer overflow that could be used to
remotely compromise machines running Microsoft-IIS.

Although Netcraft can not explicitly test for the vulnerability
without prior permission from the sites, around half of the Microsoft
IIS sites on the internet have HTR buffer overflow enabled, making it
likely that many will be vulnerable to attack.

Days later it was reported that many versions of the Apache Web server
were vulnerable to a buffer overflow because of a flaw in the Web
server's "Chunked Encoding" mechanism.

If exploited, the flaw, could lead to a remote system compromise and
exploits are already known to have been been developed for Windows,
FreeBSD and OpenBSD. There is an active debate on whether exploits are
possible for Linux and Solaris.

Netcraft reports that Apache administrators have reacted quite quickly
to the problem, and within a week of first publication, well over 6
million sites have been upgraded to Apache/1.3.26, which addresses the
problem.

That still leaves around 14 million potentially vulnerable Apache
sites, however.

Netcraft's report says: "With over half of the Internet's web servers
potentially vulnerable, conditions are ripe for an epidemic of attacks
against both Microsoft-IIS and Apache based sites, and the first worm,
targeting sites running Apache on FreeBSD, has been spotted this
weekend."

Security watchers monitoring this worm believe its spread has been
modest.

Aside from this welcome result, Netcraft notes (quiet surprisingly)  
that worms can have positive effects. It says draw administrators'
attention to vulnerable servers and - once patched - the server is
usually no longer available as a platform for more insidious activity.

Last year, immediately prior to the Code Red worm, Netcraft was
finding that around one in six ecommerce sites running Microsoft-IIS
taking a security test from Netcraft for the first time had already
been successfully compromised, and had a backdoor giving an external
attacker control over the machine.

"The clear up from Code Red had the positive effect of flushing the
majority of these backdoors out of the Internet," it notes.



-
ISN is currently hosted by Attrition.org

To unsubscribe email majordomo () attrition org with 'unsubscribe isn'
in the BODY of the mail.