Cross-Site Scripting (XSS) in GuppY

[High-Tech Bridge Security Research <advisory@xxxxxxxxxxxx>]

Advisory ID: HTB23176
Product: GuppY
Vendor: GuppY
Vulnerable Version(s): 4.6.26 and probably prior
Tested Version: 4.6.26
Advisory Publication:  October 2, 2013  [without technical details]
Vendor Notification: October 2, 2013 
Vendor Patch: October 12, 2013 
Public Disclosure: October 23, 2013 
Vulnerability Type: Cross-Site Scripting [CWE-79]
CVE Reference: CVE-2013-5983
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 two XSS vulnerabilities in 
GuppY, which can be exploited to perform Cross-Site Scripting attacks against 
users of vulnerable application.


1) Cross-Site Scripting (XSS) in GuppY: CVE-2013-5983

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

The exploitation example below uses the "alert()" JavaScript function to 
display user's cookies:

http://[host]/agenda.php?agv=2&an=%22%20onmouseover%3dalert%28%27document.cookie%27%29%20%22

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

The exploitation example below uses the "alert()" JavaScript function to 
display user's cookies:

http://[host]/mobile/thread.php?cat=1%22%20onmouseover%3dalert%28%27document.cookie%27%29%20%22

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Solution:

Update to GuppY 4.6.28

More Information:
http://www.freeguppy.org/thread.php?lng=en&pg=244900&cat=200

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References:

[1] High-Tech Bridge Advisory HTB23176 - 
https://www.htbridge.com/advisory/HTB23176 - Cross-Site Scripting (XSS) in 
GuppY.
[2] GuppY - http://www.freeguppy.org - GuppY the easy web portal that requires 
no database.
[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.
[5] ImmuniWeb® - http://www.htbridge.com/immuniweb/ - is High-Tech Bridge's 
proprietary web application security assessment solution with SaaS delivery 
model that combines manual and automated vulnerability testing.

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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.