Cisco vulnerabilities?

On Thu, 26 Aug 93 21:17:16 -0600, L. Detweiler wrote -

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Date: Wed, 25 Aug 1993 12:56:54 -0700 (PDT) From: Al Whaley Subject: Cisco routers

Rumors abound that Cisco routers have a back door; that is when a TCP port is disabled, it can still be accessed from Cisco's IP number.

I have personally verified this with the sendmail port.

Al Whaley al@sunnyside.com +1-415 322-5411(Tel), -6481 (Fax) Sunnyside Computing, Inc., PO Box 60, Palo Alto, CA 94302

Sure, they have a backdoor -- it's called unsecured ports and lackidaisical security. Cisco routers don't really have "TCP" ports, per se. They have ethernet ports, or token ring ports, v.35 serial ports, and dial-up rs-232 for fail-safe configuration when some idiot drops your feed at the local rboc and you need to "look into" your net. If the "entrance" passwords are enabled properly, then I feel quite sure that this threat is minimal. However, I have learned recently that some facets of SNMP encapsulation can exploit _management_ but can not, however exploit the configuration of the router. It can add to the traffic overhead. Also, there is an additional "enable" password for configuration modification, such as changing IP addresses of the ethernet or serial interfaces (ports) and saving the configuration to NVRAM. I had a guy adamantly try to convince me the other day that the (Cisco) routers were in jeopardy because of the ability to TFTP a new (albeit, damaging) operating system directly into NVRAM (a sleight of hand), rendering the box useless. It can be done, in fact, Cisco would have to ship me a whole new box overnight if it happened, but if I mind my P's and Q's (read: adhere to proper security), he's pissin' in the wind. ;-) Cheers, Paul Ferguson | "Government, even in its best state, Network Integrator | is but a necessary evil; in its worst Centreville, Virginia USA | state, an intolerable one." fergp@sytex.com | - Thomas Paine, Common Sense Type bits/keyID Date User ID pub 1024/1CC04D 1993/03/15 Paul Ferguson Key fingerprint = EE D2 93 7D 04 6D C6 05 AC 36 AD 9D 8E 4F 41 58