DoS in Cisco Clean Access
Date of release: 16/12/2005
Software: Cisco Clean Access/Perfigo CleanMachines
(http://www.cisco.com/en/US/products/ps6128/index.html)
Affected versions: Tested on 3.5.5, assumed all <=current.
Risk: Medium/High
Discovered by: Alex Lanstein
Background
--------
Cisco Clean Access is an easily deployed Network Admission Control solution
that can automatically detect, isolate, and clean infected or vulnerable
devices that attempt to access your network - regardless of the access method.
It identifies whether networked devices such as laptops, personal digital
assistants, or even game consoles are compliant with your network's security
policies, and repairs any vulnerabilities before permitting access to the
network.
The software that is affected resides on the Secure Smart Manager, not the
Secure Smart Server.
Details
-------
The method below has the possibility to create a denial of service on a few
layers. One, a user without a username or password can use the vulnerability
to upload files to a web visable folder for fun and profit. The user could
also fill up the drive as it seems, aside from /boot, the rest of the drive is
one big partition. Filling up the drive would most definately cause the system
to lock up in its current configuration.
In /admin/uploadclient.jsp there is a lack of authentication check so that
anyone who browses to the page can upload files directly to the web visable
folder /installer/windows. This is clearly unacceptable.
Similar types of attacks can be launched from apply_firmware_action.jsp and
file.jsp.
Solution(s)
--------
The vendor, Cisco Systems, should prepend _all_ files, especially all .jsp
files, with an authentication check. This seems to be the case with most, but
not all of the files.
The vendor should also use a better partitioning scheme in its installs.
Managers of these systems should add some sort of overall .htaccess/.htpasswd
system while they are waiting for the vendor patch, as I'm sure that under
further investigation by the engineers many more files are affected than those
listed above.
External discussion and developments:
be .aware | http://www.awarenetwork.org/forum/viewtopic.php?p=2236