Messages in this thread | | | Date | Sun, 12 Jun 2005 23:13:23 +1000 | Subject | Re: [PATCH] fix small DoS on connect() (was Re: BUG: Unusual TCP Connect() results.) | From | Herbert Xu <> |
| |
On Sun, Jun 12, 2005 at 02:32:53PM +0200, Willy Tarreau wrote: > > but it's not the case (although the naming is not clear). So if the remote > end was the one which sent the SYN-ACK, it will clear its session. If it has > been spoofed, it will ignore the RST because in turn, the SEQ will not be > within its window.
This is what should happen:
1) client A sends SYN to server B. 2) attcker C sends spoofed SYN-ACK to client A purporting to be server B. 3) client A sends RST to server B.
The RST packet is sent by client A using its sequence numbers. Therefore it will pass the sequence number check on server B.
4) server B resets the connection.
Cheers, -- Visit Openswan at http://www.openswan.org/ Email: Herbert Xu ~{PmV>HI~} <herbert@gondor.apana.org.au> Home Page: http://gondor.apana.org.au/~herbert/ PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
| |