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ssh dos
From: Balla István <balla.bmf () gmail com>
Date: Sun, 19 May 2013 18:33:12 +0200

Hey guys,

I launched a DoS attack against SSH service on target host. topology looks
very simple:


After a while snort blocked it but with Protocol mismatch(4:128) not with
DoS rule.

my ssh preproc setting in snort.conf:

preprocessor ssh: server_ports { 22 } \
                  autodetect \
                  max_client_bytes 0 \
                  max_encrypted_packets 20 \
                  max_server_version_len 80 \
                  enable_respoverflow enable_ssh1crc32 \
                  enable_srvoverflow enable_protomismatch

I attach the pcap on the target host. I used a simple attacker tool
simulating 1000 parallel requesting threads.
If you have a couple of time could you take a look to the files? I wonder
why dos rule was inactive (it is included).


Attachment: dos_ssh.pcap

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