It seems to be fairly well known that there are multiple unpatched
CSRF vulnerabilities in the administration interfaces for various
Linksys routers. Since the initial reports of these are from a few
years ago, and since some exploits are available, I have written
additional proof of concept exploits for the Linksys routers that I
have access to.
While in most cases the victim must be authenticated with the
application in question to exploit a CSRF vulnerability, since the
factory default passwords for all of the routers in question are known
to be admin, the victim does not necessarily need to be authenticated.
This means that only suggested workaround that I have seen up until
now, do not surf the web wile authenticated in the router's
administration interface, does not solve the problem in certain cases
where the user is still using the default password. This is mitigated
somewhat by the fact that most browsers provide at least some degree
of protection from these types of attacks, described in additional
detail below.
In each case, the proof of concept will enable remote administration
of the router on port 31337, while changing the password to __pwn3d__.
WRT54G2 PoC (tested with hardware version 1.5 and firmware version 1.50):
WRT54G2 CSRF PoC
The form's action can be changed in the following way to attempt to
log in with the default password:
To attempt a login with the default password, the same type of
modification can be made, as shown here: