[Snort-sigs] SID 1129 documentation

Kevin Peuhkurinen kevin.peuhkurinen at ...1555...
Tue Jun 10 06:23:11 EDT 2003


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Rule:  
alert tcp $EXTERNAL_NET any -> $HTTP_SERVERS $HTTP_PORTS (msg:"WEB-MISC 
.htaccess access"; flow:to_server,established; content:".htaccess"; 
nocase; classtype:attempted-recon; sid:1129; rev:4;)
--
Sid:
1129
--
Summary:
A client is requesting the file ".htaccess" from your web server.
--
Impact:
If this request is successful, it could provide an attacker with 
valuable information needed to compromise your website.
--
Detailed Information:
Most *nix based web servers, such as Apache and Netscape Enterprise 
Server, use ".htaccess" files to customize security settings on a 
per-directory level.   These files can specify things like what users 
have access to what resources,
hosts that are allowed or denied, and what type of authentication system 
to use.   This type of data would be most useful for carrying out an 
attack on the site.   Fortunately, all modern web servers deny client 
access to these files by default.
--
Affected Systems:
Any system that uses ".htaccess" files and which have misconfigured the 
server to allow client access to them.
--
Attack Scenarios:
This is an information gathering operation which could facilitate an attack.
--
Ease of Attack:
It is simple to send a request for this file, but the request would only 
be successful if the file exists and the server allows access to it.
--
False Positives:
While unlikely, certain web servers that are set up to host multiple 
users' sites may allow access to this file by the site owners.
--
False Negatives:
None known.
--
Corrective Action:
First determine if the attack is successful by requesting the file 
yourself.   If the request is granted, ensure that your web server is 
configured to deny access to all files that begin with ".ht".
--
Contributors:
Kevin Peuhkurinen
-- 
Additional References:
http://www.webdeveloper.com/servers/servers_htaccess_magic.html






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