Advisory ID: HTB23139
Product: Events Manager WordPress plugin
Vendor: Marcus Sykes
Vulnerable Version(s): 5.3.3 and probably prior
Tested Version: 5.3.3
Vendor Notification: January 16, 2013 
Vendor Patch: January 17, 2013 
Public Disclosure: March 6, 2013 
Vulnerability Type: Cross-Site Scripting [CWE-79]
CVE Reference: CVE-2013-1407
Risk Level: Medium 
CVSSv2 Base Score: 4.3 (AV:N/AC:M/Au:N/C:N/I:P/A:N)
Solution Status: Fixed by Vendor
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 XSS vulnerabilities in Events Manager WordPress plugin, which can be exploited to perform Cross-Site Scripting attacks.


1) Multiple XSS vulnerabilities in Events Manager WordPress plugin: CVE-2013-1407

1.1 The vulnerability exists due to insufficient filtration of user-supplied data in "scope" HTTP GET parameter passed to "/index.php" script. A remote attacker can trick user to open a specially crafted link and execute arbitrary HTML and script code in browser in context of the vulnerable website.

PoC (Proof-of-Concept) below uses the "alert()" JavaScript function to display user's cookies: 

http://[host]/?page_id=42&scope=%22%3E%3Cscript%3Ealert%28document.cookie%29;%3C/script%3E,%22%3E%3Cscript%3Ealert%28document.cookie%29;%3C/script%3E


1.2 The vulnerability exists due to insufficient filtration of user-supplied data in "_wpnonce" HTTP GET parameter passed to "/wp-admin/edit.php" script. A remote attacker can trick logged-in administrator to open a specially crafted link and execute arbitrary HTML and script code in browser in context of the vulnerable website.

PoC (Proof-of-Concept) below uses "alert()" JavaScript function to display administrator's cookies: 

http://[host]/wp-admin/edit.php?post_type=event&page=events-manager-bookings&_wpnonce=%22%3E%3Cscript%3Ealert%28document.cookie%29;%3C/script%3E


1.3 The vulnerabilities exist due to insufficient filtration of user-supplied data in "user_name", "dbem_phone" and "user_email" HTTP GET parameters passed to "/index.php" script. A remote attacker can trick user to open a specially crafted link and execute arbitrary HTML and script code in browser in context of the vulnerable website.

PoCs (Proof-of-Concept) below use the "alert()" JavaScript function to display user's cookies: 

http://[host]/?event=1&user_name=%27%3E%3Cscript%3Ealert%28document.cookie%29;%3C/script%3E
http://[host]/?event=1&dbem_phone=%27%3E%3Cscript%3Ealert%28document.cookie%29;%3C/script%3E
http://[host]/?event=1&user_email=%27%3E%3Cscript%3Ealert%28document.cookie%29;%3C/script%3E


1.4 The vulnerability exists due to insufficient filtration of user-supplied data in "booking_comment" HTTP POST parameter passed to "/index.php" script. A remote attacker can trick user to open a specially crafted link and execute arbitrary HTML and script code in browser in context of the vulnerable website.

PoC (Proof-of-Concept) below uses the "alert()" JavaScript function to display user's cookies: 


<form action="http://[host]/?event=1" method="post" name="askform">
<input type="hidden" name="booking_comment" value="</textarea><script>alert(document.cookie);</script>"/>
<input type="submit" id="btn">
</form>


Vulnerabilities 1.3 and 1.4 will work only against unauthorized (not logged-in) users. Successful exploitation of these vulnerabilities also requires that event with id = 1 has turned-on registration. 


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Solution:

Upgrade to Events Manager 5.3.4

More Information:
http://wordpress.org/extend/plugins/events-manager/changelog/
http://wp-events-plugin.com/blog/2013/01/22/5-3-5-released-includes-a-security-update/

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References:

[1] High-Tech Bridge Advisory HTB23139 - https://www.htbridge.com/advisory/HTB23139 - Multiple XSS vulnerabilities in Events Manager WordPress plugin.
[2] Events Manager - http://wp-events-plugin.com - Events Manager is a full-featured event registration plugin for WordPress based on the principles of flexibility, reliability and powerful features.
[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.
[4] Common Weakness Enumeration (CWE) - http://cwe.mitre.org - targeted to developers and security practitioners, CWE is a formal list of software weakness types. 

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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.