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Re: TCP/BGP vulnerability - easier than you think
On 21-apr-04, at 14:38, Daniel Roesen wrote:
So the attacker sends a spoofed SYN to router A, and router A sends an RST to router B and router B terminates the BGP session.
The good part here is that filtering RSTs should still work.
It doesn't. The RST are then being sent by the authorized sender andNow it's your time to overlook something: the filters I listed in my earlier message simply filter RSTs to/from the BGP port without looking at the address fields. Filtering ALL RSTs is probably a bad idea as broken sessions will then have to time out, possibly inconveniencing users (and thereby generating support calls). But for BGP this isn't much of an issue as the BGP hold timer takes care of business here anyway. So I believe filtering out all BGP RSTs on all edges is probably a good idea.