[Snort-users] Problem with http_inspect and Basic Authentication rule

andreas andi at ...15330...
Mon Jul 4 06:31:53 EDT 2011

Hi *,

i use snort on a mirror port. I found an issue with http_inspect
preprocessor and one rule for authentication.
I start snort using "--treat-drop-as-alert -u snort -g snort -A
fast -N -I -i eth2 -P 0 -l /var/log/snort -c /etc/snort/snort.conf".
I also tried several options with the "preprocessor http_inspect:". The
rule i want to see in the log file is:

"ET POLICY Outgoing Basic Auth Base64 HTTP Password detected unencrypted"

with sid:2006380, which is in "emerging-policy.rules".

I use two lynx calls to test this issue ( is just an example IP):

1. lynx --auth=foo:bar
2. lynx and then navigate to login and try
to authenticate

When http_inspect is activated, the alert only occurs with the fist
call. If i put "disabled" to the preprocessor http_inspect the alert
occurs on both calls. So the rule is fine and the packages are also
fine, so i can point it down to the http_inspect. One idea is, that with
http_inspect activated only the first HTTP Requests are handled and the
HTTP alert for the authentication is ignored.

I tried to play with all the http_inspect options but no change except
for the disabled option.

So any idea what i can do/try to get snort working with http_inspect and
still reporting the alert for the authentication when the loginpage
isn't called directly?


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