Heads-up: Major Linux BASH Vulnerability

[Magnox]

In case anyone has missed this, a major exploit in BASH has been discovered and made public a couple of days ago. It effects OpenSSH too. I've only just seen the news (removes head from sand...)

Just google it for info.

Anyone on Linux kit, do the necessary!

[George]

Any idea if this means that Linux based routers are vulnerable to remote attacks?

[Magnox]

Possibly yes, according to Symantec:

"Aside from Web servers, other vulnerable devices include Linux-based routers that have a Web interface that uses CGI. In the same manner as an attack against a Web server, it may be possible to use CGI to exploit the vulnerability and send a malicious command to the router."

[Cain]

Any "easy" way to test to see if a router is vulnerable?

[SB7]

Most routers ( consumer ) use Busybox which uses "ASH" not bash and thus are not unacceptable to Shellshock.  ( It does appear that linksys , cisco may be running bash)
Secondly, this is only a problem if you allow external web based config of your router.  Typically that is turned off to only allow the web page config to be used from within the network
Of course you could be running telnet or SSH without a password .... that would be unwise. But then that's always been unwise.
To see if bash is even installed you could ssh into your router and try to execute "bash"  I doubt it's even installed.

[Cain]

Thanks for clarifying SB7. I do have the remote admin on since I need it and will check via Telnet/SSH. One thing that I did now was to only allow the specific IP-range from my work.

[SB7]

You could try an external test to "probe you from the outside" :-)

h_ttp://shellshock.brandonpotter.com/

Enter your external IP and see if what you are presenting to internet is vulnerable

[Cain]

I'm safe ... Here are two more...

h_ttp://www.shellshocktest.com

h_ttp://bashsmash.ccsir.org

Checked www.sonsivri.to as well and that server running it looks safe as well.