Full Disclosure mailing list archives

RE: SSH Bruteforce blocking script


From: "Michael L Benjamin" <mike.benjamin () clarinet com au>
Date: Fri, 2 Sep 2005 16:30:30 +0800

 

Ok, well spotted. Something for me to fix there.

Here you go, add these lines to the script just after the touch:

chmod 700 ${TMP_FILE}
${TMP_FILE}

My apologies, that is a no-no and something I should have spotted.

I originally thought about doing this with arrays in memory. I might go back to that later.

Thanks for your input.

Cheers, Mike.



-----Original Message-----
From: full-disclosure-bounces () lists grok org uk [mailto:full-disclosure-bounces () lists grok org uk] On Behalf Of 
Alejandro Barrera
Sent: Friday, September 02, 2005 04:04 PM
To: full-disclosure () lists grok org uk
Subject: Re: [Full-disclosure] SSH Bruteforce blocking script

Well, we apreciate your script although I would preffer to stay with my nice bruteforcing attempts than to create an 
insecure temporary file bug:

ergosum@sparta:~$ cat test.sh
#!/bin/sh

SCRIPT_NAME=$(basename $0)
TMP_FILE="/tmp/${SCRIPT_NAME}.$$"

touch ${TMP_FILE}
echo "pwn3d" > ${TMP_FILE}
exit
ergosum@sparta:~$ cat data
pr0n g0ld collection: ....

ergosum@sparta:~$ ln -s /home/ergosum/data /tmp/test.sh.18359 ergosum@sparta:~$ ln -s /home/ergosum/data 
/tmp/test.sh.18361 ergosum@sparta:~$ ln -s /home/ergosum/data /tmp/test.sh.18362 ergosum@sparta:~$ ./test.sh 
ergosum@sparta:~$ cat data pwn3d


#!/bin/ksh
#
# ssh_brute_blocker
#
# 05/07/2004 15:05 - Michael L. Benjamin #
 
SCRIPT_NAME=$(basename $0)
LOG_FILE="/var/log/secure"
DENY_FILE="/etc/hosts.deny"
TMP_FILE="/tmp/${SCRIPT_NAME}.$$"
INBOUND_IP=""
INLINE=""
GUESS_COUNT=0
PERMIT_GUESS=4
 
touch ${TMP_FILE}
 
while :
do
 
tail -10000 ${LOG_FILE} | grep "Failed password for illegal user" | 
awk -F"from" {'print $2'} | awk {'print $1'} | uniq > ${TMP_FILE}

 
 
 


--
Alejandro Barrera GarcĂ­a-Orea
R&D Engineer
c/ Alcala 268 28027 Madrid
Office: +34 91 326 66 11
Fax: +34 91 326 66 11
e-mail: abarrera () iron-gate net

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