Security problem in PPPoE connection
bora at broadcom.com
Mon Mar 13 19:16:25 UTC 2006
Any info on percentages of users that use routers vs Windows boxes?
> Microsoft has some suggestions for configuring PPPOE for MS-Windows.
> A problem is many of your customers won't follow the
> directions, and may still be vulnerable to man-in-the-middle
> attacks for the login if they don't disable PAP. Because
> things will appear to work, i.e. Windows will use CHAP first
> and fallback to PAP, your customers may not notice when an
> attack does occur.
> Although PPPOE is a layer 2 protocol, the user data may be
> vulnerable to many of the same ethernet CAM table, denial of
> service and sniffing weaknesses even if the login credentials
> are kept secret with CHAP (or more advanced EAP options).
> PPPOE and PPP tend to assume the access networks are 1)
> "free" and 2) "secure." This may be constrained using
> point-to-point connections, but often require additional
> configuration of multi-access networks.
> The configuration details will vary by equipment vendor. But
> you should find some good information by doing a few web
> searches for metro ethernet security, private vlan, broadcast
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