Month: May 2012

bookmark_borderFaking (all) user agents

Posted on by Daniel Cid

If you are going to fake a user agent, do it right 🙂 Seeing some web scanners faking all possible browsers out there in one single request:

  • Firefox/3.6
  • Chrome/9
  • Firefox/3.0
  • Opera/9.99?
  • Safari
  • and more..

This is the actual log (searching for vulnerable oscommerce files):

66.147.240.166 – – [24/May/2012:13:50:50 +0000] “GET /admin/file_manager.php/login.php HTTP/1.1” 404 9152 “-” “Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9.2.12) Gecko/20101026 Firefox/3.6.12\”,\”Mozilla/5.0 (Windows; U; Windows NT 5.1; pl-PL; rv:1.8.1.24pre) Gecko/20100228 K-Meleon/1.5.4\”,\”Mozilla/5.0 (X11; U; Linux x86_64; en-US) AppleWebKit/540.0 (KHTML,like Gecko) Chrome/9.1.0.0 Safari/540.0\”,\”Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US) AppleWebKit/532.5 (KHTML, like Gecko) Comodo_Dragon/4.1.1.11 Chrome/4.1.249.1042 Safari/532.5\”,\”Mozilla/5.0 (X11; U; Linux i686 (x86_64); en-US; rv:1.9.0.16) Gecko/2009122206 Firefox/3.0.16 Flock/2.5.6\”,\”Mozilla/5.0 (Windows; U; Windows NT 6.0; en-US) AppleWebKit/533.1 (KHTML, like Gecko) Maxthon/3.0.8.2 Safari/533.1\”,\”Mozilla/5.0 (Windows; U; Windows NT 6.0; en-US; rv:1.8.1.8pre) Gecko/20070928 Firefox/2.0.0.7 Navigator/9.0RC1\”,\”Opera/9.99 (Windows NT 5.1; U; pl) Presto/9.9.9\”,\”Mozilla/5.0 (Windows; U; Windows NT 6.1; zh-HK) AppleWebKit/533.18.1 (KHTML, like Gecko) Version/5.0.2 Safari/533.18.5\”,\”Seamonkey-1.1.13-1(X11; U; GNU Fedora fc 10) Gecko/20081112\”,\”Mozilla/5.0 (compatible; MSIE 9.0; Windows NT 6.1; Win64; x64; Trident/5.0; .NET CLR 2.0.50727; SLCC2; .NET CLR

I wonder if it is a bug in their scanners or they did on purpose to bypass user agent restrictions.

bookmark_borderOSSEC rule for the PHP-CGI vulnerability

Posted on by Daniel Cid

I am seeing many scans for the PHP-CGI vulnerability in the wild and put up a quick OSSEC rule to detect/block those:

<rule id="31110" level="6">
<if_sid>31100</if_sid>
<url>?-d|?-s|?-a|?-b|?-w</url>
<description>PHP CGI-bin vulnerability attempt.</description>
<group>attack,</group>
</rule>

 
It looks for the possibly dangerous options (-d,-s,-a,-b and -w) and alerts if it sees those. This is the alert it generates when detected:

** Alert 1336547515.182029: - web,accesslog,attack,
2012 May 09 03:11:55 (honeypot3) any->/var/log/httpd/access.log
Rule: 31110 (level 6) -> 'PHP CGI-bin vulnerability attempt.'
Src IP: 93.233.72.66
93.233.72.66 - - [09/May/2012:07:11:55 +0000] "GET /index.php?-s HTTP/1.1" 200 39479 "-" "Mozilla/5.0 (Windows NT 6.1; WOW64; rv:12.0) Gecko/20100101 Firefox/12.0"

This rule is also in my repository and you can download the latest from here.

bookmark_borderDatabase Logging (PostgreSQL and MySQL)

Posted on by Daniel Cid

Nobody cares about database logging, but I really recommend enabling them to see what is happening behind the scenes (specially for web applications).

To enable on PostgreSQL (and be compatible with OSSEC):

# Adding the timestamp, hostname and database.
log_line_prefix = '[%m] %h:%d '

# Recommended settings:
log_connections = on
log_disconnections = on
log_duration = on

# Maybe a good idea to reduce the default log level to info:
client_min_messages = info
log_min_messages = info

# To enable query logging (all for everything or mod for inserts, updates, etc)
log_statement = 'all'

On MySQL:

To enable the generic Query log on MySQL (the error log in on by default), you need to start MySQL with –log:

/bin/sh /usr/bin/mysqld_safe --log

The best option is to modify /etc/init.d/mysqld (if using Centos) and inside the –log in there.

Nothing new, but I was searching for this information online and couldn’t find much info.