DoS attack in the wild

luben karavelov luben at
Fri Jun 19 22:45:01 MSD 2009

A DoS attack against number of http servers is available and has hit 
slashdot today:

Out of the box nginx is also vulnerable (I have tested it on latest 0.7 
installation). A quick fix for the vulnerability follows:

Put in "http" section:

client_body_timeout 10;
client_header_timeout 10;
keepalive_timeout 10;
send_timeout 10;
limit_zone limit_per_ip $binary_remote_addr 1m;

and put in "server" section :

limit_conn limit_per 16;

The last 2 configuration lines are for limiting connections per client 
IP. This fist lines are same sane connection timeouts.

Best regards and keep the great work!

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