Re: - Cisco IOS HTTP Server code injection/execution vulnerability-

[Florian Weimer <fw () deneb enyo de>]

> It has been identified a vulnerability in the Cisco IOS Web
> Server. An attacker can inject arbitrary code in some of the
> dynamically generated web pages. To succesfully exploit the
> vulnerability the attacker only needs to know the IP of the
> Cisco. THERE'S NO NEED TO HAVE ACCESS TO THE WEB SERVER! Once the
> code has been inyected, attacker must wait until the admin browses
> some of the affected web pages.

Isn't your exploit somewhat complicated?  Just put

<img src="http://192.0.2.1/level/15/configure/-/enable/secret/mypassword"/>

on a web page, and trick the victim to visit it while he or she is
logged into the Cisco router at 192.0.2.1 over HTTP.  This has been
dubbed "Cross-Site Request Forgery" a couple of years ago, but the
authors of RFC 2109 were already aware of it in 1997.  At that time,
browser-side countermeasures were proposed (such as users examining
the HTML source code *cough*), but current practice basically mandates
that browsers transmit authentication information when following
cross-site links.

Such attacks are probably more problematic on low-end NAT routers
whose internal address defaults to 192.168.1.1 and which generally
offer HTTP access, which makes shotgun exploitation easier.  So much
for the "put your Windows box behind a NAT router" advice you often
read.