Security Basics mailing list archives
RE: VALN hopping
From: "Joshua Berry" <JBerry () PENSON COM>
Date: Wed, 5 Oct 2005 13:03:41 -0500
VLAN's can certainly be bypassed as long as they are not setup properly. @stake did a security review of VLAN's which can be found here: http://www.cisco.com/warp/public/cc/pd/si/casi/ca6000/tech/stake_wp.pdf And cisco has their own documentation on it here: http://www.cisco.com/warp/public/cc/pd/si/casi/ca6000/prodlit/vlnwp_wp.p df These outline potential problems and their solutions. I would be a little skeptical if it was only Cisco doing the research into VLAN exploitation but I am a little more comfortable since @stake did research into it as well. -----Original Message----- From: Steve McLaughlin [mailto:Steve.McLaughlin () aggreko co uk] Sent: Wednesday, October 05, 2005 6:28 AM To: David Barroso; Hayes, Ian Cc: security-basics () securityfocus com Subject: RE: VALN hopping According to Cisco they are a good security measure. I don't know of any exploits which enable you to VLAN hop. Does anyone know of any? On a layer 2 switch the ports are physically assigned to a VLAN, and therefore require a Layer 3 device to route traffic between them. On a layer 3 switch this might be different because of it's layer 3 capabilities built into the appliance. Though, I still don't know of any way of 'VLAN Hopping', although I could be wrong. And if this is possible on a layer 2 switch then please explain? Steve McLaughlin - Security Analyst (CCNP, MCSE:Security, Security+) -----Original Message----- From: David Barroso [mailto:dbarroso () s21sec com] Sent: 30 September 2005 18:54 To: Hayes, Ian Cc: security-basics () securityfocus com Subject: Re: VALN hopping
WWe are having a heated discussion about using VLAN's as a type of DMZ, soI am asking the experts. I prsonally like to see physical
isolation;
however, our network person doesn't feel there is a threat of VLAN hopping. Please let me know your opinions.
If they are new devices with up-to-date OS versions it is not very likely that attacks similar to double encapsulated 802.1q packets will succeed. On the other hand, if they are not properly configured and/or hardened, other attacks can be accomplished, like for instance, with Cisco devices, setting up a trunking if DTP settings are poorly configured (see http://yersinia.sourceforge.net for performing that attack). -- David Barroso Berrueta Not one day goes by that I don't ride, 'til the infinite, the horse of my imagination ______________________________________________________________________ This email has been scanned by the MessageLabs Email Security System. ______________________________________________________________________ Visit us at http://www.aggreko.com Confidentiality Notice: This communication and any accompanying attachments contain confidential information intended for a specific individual and purpose. This communication is private and protected by law. If you are not the intended recipient, you are hereby respectfully notified that any disclosures, copying, forwarding or distribution, or the taking of any action based on the contents of this communication is strictly prohibited. _____________________________________________________________________ This email has been scanned by the MessageLabs Email Security System. For more information please visit http://www.messagelabs.com/email ______________________________________________________________________
Current thread:
- RE: VALN hopping Bryan S. Sampsel (Oct 03)
- <Possible follow-ups>
- Re: VALN hopping Micheal Espinola Jr (Oct 03)
- RE: VALN hopping Craig Wright (Oct 04)
- RE: VALN hopping Steve McLaughlin (Oct 05)
- Re: VALN hopping David Barroso (Oct 06)
- RE: VALN hopping Joshua Berry (Oct 06)
- RE: VALN hopping Joshua Berry (Oct 06)
- Re: VALN hopping David Barroso (Oct 06)