oss-sec mailing list archives
Re: Zimbra XSS in aspell.php, CVE request
From: Jeff Flanigan <jflanigan () zimbra com>
Date: Tue, 9 Apr 2013 10:36:53 -0700 (PDT)
Filed https://bugzilla.zimbra.com/show_bug.cgi?id=81588 for 8.0.4. Thanks for the clarification of what we missed in bug 79640. -Jeff ----- Original Message ----- From: "Kurt Seifried" <kseifried () redhat com> To: oss-security () lists openwall com Cc: "Michael Scherer" <misc () zarb org>, security () vmware com, security () zimbra com Sent: Tuesday, April 9, 2013 10:21:11 AM Subject: Re: [oss-security] Zimbra XSS in aspell.php, CVE request -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 On 04/05/2013 06:14 PM, Michael Scherer wrote:
Le vendredi 05 avril 2013 à 18:05 -0600, Kurt Seifried a écrit :On 04/05/2013 04:21 AM, Michael Scherer wrote:Hi, While trying to see how hard a bug would be to fix in Zimbra during a discussion with a coworker, I stumbled across a XSS flaw in Zimbra, in a spell checking external webservice. Since I didn't found the public web interface for the source code of Zimbra and since perforce is not as straightforward to run on linux than git and slow to download the 2G of source code, I recommend to people to look at the github mirror, even if this mean losing some information and changelog. The issue is on this file : https://github.com/Zimbra-Community/zimbra-sources/blob/master/main/ZimbraServer/src/php/aspell.php
The problem is that $dictionary is coming from user input ( from
GET parameters ), since it is a copy of $_REQUEST. Then if no text is given ( and so $text is empty ), it is printed back in the html form displayed without any kind of sanitization at all ( line133 : https://github.com/Zimbra-Community/zimbra-sources/blob/master/main/ZimbraServer/src/php/aspell.php#L133
)
So a attacker could inject javascript/html there just by giving crafted link to a user, running as the domain of zimbra ( albeit on a different port ). Something like http://example.org/aspell.php?disctionnary=><script> alert('foo');</script> ( with proper url encoding of course ). Due to typecasting, "" is considered as equal to NULL for '==', while it may not be the case in other circumstances. If I am not wrong, the default location for the spell checking service is http://$config{HOSTNAME}:7780/aspell.php, so a improperly secured server ( ie, without a firewall ) could be vulnerable to javascript injection, which could be used to steal various informations ( like the session cookie ). However, depending on the browser and the security setting, the issue could be mitigated, even if it seems we can still steal the cookie with a spear phising attempt ( http://seckb.yehg.net/2012/06/xss-gaining-access-to-httponly-cookie.html
)
The issue can be tested quite easily, just take any php hosting, download the aspell.php file there and run : $ curl 'http://www.example.org/aspell.php?dictionary=insert_html_here_with<blink>'
You should see that the html code is inserted back in the form. I
didn't spent time on writing a trivial exploit for that. Upstream have been notified on 2013-01-12 on a private bug ( https://bugzilla.zimbra.com/show_bug.cgi?id=79640 ), with first answer on 2013-02-22, along with a fix following on the next hours. However, the fix is incorrect, and my attempt to make the coder change his mind failed. The fix that was written can be found on a aggregate commit on https://github.com/Zimbra-Community/zimbra-sources/commit/e7682c00be82a0c3ab51ee92f518bdcc1e07536c#L3L148
While that could fix a XSS issue if the code was correctly used,
there was no security issue since the call of the function is wrong on line 67, we see 1 parameter is missing and the value of $dictionnary is overwrote by the return code and is always 0, so we cannot inject anything with it. As I couldn't convince upstream to correct this, and given that I have let enough time to react to them after following the procedure, I consider that full disclosure is the next step to have it corrected. Can someone assign a CVE for it ?Is this also in the open source version? http://wiki.zimbra.com/wiki/Building_Zimbra_using_PerforceI only used the open source version ( since I doubt the other version is cloned on github, that would kinda be a license violation ) and I do not have access to the closed source one ( or rather, i didn't tried very hard to have access to it to check, as I would not be able to link to source code for verification ) However, I suspect that's the same for non open source one ( ie, I see no reason to have less features in the commercial version )
Ah sorry misread, thought you were testing against a live commercial zimbra install the first time. Also added vmware/zimbbra security (hopefully those email addresses exist) to the CC. Please use CVE-2013-1938 for this issue. - -- Kurt Seifried Red Hat Security Response Team (SRT) PGP: 0x5E267993 A90B F995 7350 148F 66BF 7554 160D 4553 5E26 7993 -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.13 (GNU/Linux) iQIcBAEBAgAGBQJRZE4HAAoJEBYNRVNeJnmTDvEQAJvDKrNsmwkPnCACLh61mTcd rQr152bq8RQZOmNTL/jfpqH2KX/O8SGFH8Ptc2JBHu1im+s0CVn0ABdjbDylf524 F2F03A45gpHKX4XF9kRTLC48LopgyQE/1JDL4WYwoV8KR6RVELfyeXMUaP9nCe6r UEjyWOE5F8y7TI2MPbtnHaPcGo2sXCDv/giGYikb5Y4L3M33Bd88zRe5NM0G08G4 KXnoeMRlwCtAQ5KXrV90X+vtPFLPLPQHOdmXBJk4unYXMQuT7ookfzS042bzPR5f 7m/qgMrc9ra3Ye4zaG6yeUj/cSAyrh2npsF/IJCMBf0SGb3eg7boRB/g8cDb7KyD oWLTYCtqn60ALa/6d4igmDrX8ihheunDHMZU5Quy/W5CVl2CfmmVhWBf8RW+RzQN W/ZXX1S36QMAcxFG6Y4omhrMPygs2dx8oell1ed/3NpA738DiZf4riZDH0vde3d6 MN+77inJV82GkiVWDlgaPhxfNYzakV3Bzo/whH5GxUz5RKnBYu4PGinpdPt/waKx 5Kyb5nhfJlyhhD550BVTtX0YtbBiBWE4rasQO72qaeLoyB27ijETvuIHWa52HZA9 76oWVQI0SU9b/zZIFohikdrzs2QqvzjsYyN/YdvjBdpQbNayNEYZYHI0QgjNNymp z/7/IBCnFvWQ2cP35VE5 =OXAN -----END PGP SIGNATURE-----
Current thread:
- Zimbra XSS in aspell.php, CVE request Michael Scherer (Apr 05)
- Re: Zimbra XSS in aspell.php, CVE request Kurt Seifried (Apr 05)
- Re: Zimbra XSS in aspell.php, CVE request Michael Scherer (Apr 05)
- Re: Zimbra XSS in aspell.php, CVE request Kurt Seifried (Apr 09)
- Re: Zimbra XSS in aspell.php, CVE request Jeff Flanigan (Apr 09)
- Re: Zimbra XSS in aspell.php, CVE request Michael Scherer (Apr 05)
- Re: Zimbra XSS in aspell.php, CVE request Kurt Seifried (Apr 05)