#2008-012 Horde, Popoon frameworks common input sanitization errors (XSS)

Two cross-site scripting (XSS) vulnerabilities were reported in Horde
Framework. The first of which is that the Horde framework fails to properly
sanitize the filename of MIME attachments on received emails.  The second
vulnerability has a wider impact.

Horde relies on code similar to Popoon's externalinput.php to filter out
potential XSS attacks on user-supplied input.  This filter, and the original,
fail to fully sanitize user data.  In particular, this filter fails to
protect against '/'s acting as spaces in both Microsoft Internet Explorer and
Mozilla Firefox.

Patches have been made available for Horde:

* 3.1:
  http://ocert.org/patches/2008-012/Text_Filter.31.patch
* 3.2 - CVS HEAD:
  http://ocert.org/patches/2008-012/MIME.patch
  http://ocert.org/patches/2008-012/Text_Filter.patch

A replacement for externalinput.php is linked below as well.


Affected version:

Popoon (externalinput.php) <= r22196

Horde >= 3.2, <= 3.2.1 (both issues)
Horde >= 3.1, <  3.2   (XSS filter only)

(secondary affected versions)

Horde Groupware >= 1.0, <= 1.0.6 (XSS filter only)
Horde Groupware Webmail Edition >= 1.0, <= 1.0.7 (XSS filter only)
Horde Groupware >= 1.1, <= 1.1.2 (both issues)
Horde Groupware Webmail Edition >= 1.1, <= 1.1.2 (both issues)
Cake-PHP <= 1.2.0.7296 RC2
phpMyFAQ <= 2.5.0-dev (2008-08-18)
deluxeBB <= 1.2
emucms <= 0.3
SimpleSite <= 1.6.4
RevokeBB <= 1.0RC11_normal
TPLN <= 2.9
Logicoder <= r27
phour <= r106
MDPro <= 1.0821
noserub <= r784/0.6


Fixed version:

Horde > 3.2.1 (see patches)

externalinput/clean.php (see links)


Credit: Vulnerability report and proof of concepts received from
        Alexios Fakos <security [at] nruns [dot] com>.


CVE: CVE-2008-3823 (MIME attachment), CVE-2008-3824 (XSS filtering)


Timeline:
2008-08-05: initial report and proof of concepts received.
2008-08-18: affected software survey completed by oCERT.
2008-08-18: externalinput.php/Popoon author contacted.
2008-08-19: Horde author contacted.
2008-08-19: initial patches for Horde and Popoon supplied by vendors.
2008-08-19: reporter calls out additional possible vectors in externalinput.php.
2008-08-20: secondary fixed for externalinput.php supplied.
2008-08-20: attempted to contact CakePHP.
2008-09-04: final Horde patches supplied.
2008-09-04: potentially affected oCERT members and vendor-sec notified.
2008-08-05: CVEs assigned.
2008-09-05: oCERT requests end of embargo to be Sep 10, 1700 UTC.
2008-09-06: contacted phlymail lite; confirmed unaffected.
2008-09-06: notified all secondary vendors above.
2008-09-06: acknowledgement from cakephp, noserub, phpmyfaq.
2008-09-09: confirmed exact embargo end with vendor-sec and other vendors.
2008-09-10: advisory released.

References:
http://blog.liip.ch/archive/2005/01/16/xss-how-we-try-to-prevent-it.html
http://blog.liip.ch/missed-case-in-externalinput-php-resulting-in-viable-xss-attacks.html

Links:
http://horde.org
http://svn.bitflux.ch/repos/public/popoon/trunk/classes/externalinput.php
https://svn.liip.ch/repos/public/ext/externalinput/trunk/lx/externalinput/clean.php
http://horde.org/groupware
http://www.cakephp.org
http://www.phpmyfaq.de
http://www.deluxebb.com
http://www.emusoft.org/index.php?page=category&cat_id=14
http://dev.mistralys.com/SimpleSite
http://sourceforge.net/projects/revokebb
http://tpln.h2lsoft.com/
http://code.google.com/p/logicoder/
http://code.google.com/p/phour/
http://www.maxdev.com/AboutMD.phtml
http://code.google.com/p/noserub/
http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2008-3823
http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2008-3824

Permalink:
http://www.ocert.org.org/advisories/ocert-2008-012.html


--
Will Drewry <redpig@ocert.org>
oCERT Team :: http://ocert.org