WordPress iframe 3.0 Stored Cross Site Scripting

Posted on Posted in Exploit

WordPress iframe plugin version 3.0 suffers from a stored cross site scripting vulnerability.

Software: iframe
Version: 3.0
Homepage: http://wordpress.org/plugins/iframe/
Advisory report: https://security.dxw.com/advisories/stored-xss-in-iframe-allows-less-privileged-users-to-do-almost-anything-an-admin-can/
CVE: Awaiting assignment
CVSS: 5.5 (Medium; AV:N/AC:L/Au:S/C:P/I:P/A:N)

Stored XSS in iframe allows less privileged users to do almost anything an admin can

Users without the unfiltered_html capability are able to insert arbitrary HTML into pages and thus exceed the privileges they were granted.

Proof of concept
Insert the following into a post:
[iframe src=\"http://www.youtube.com/embed/4qsGTXLnmKs\" width=\"100%\" height=\"500\" onload=\"alert(1)\"]

Disable the plugin until a new version is released that fixes this bug.
The vendor has released version 4.0 in which onload is disabled, but the other ‘event’ attributes are still permitted, including onpageshow. A number of these event attributes could be used to execute this attack, so this issue is not resolved.

Disclosure policy
dxw believes in responsible disclosure. Your attention is drawn to our disclosure policy: https://security.dxw.com/disclosure/

Please contact us on security@dxw.com to acknowledge this report if you received it via a third party (for example, plugins@wordpress.org) as they generally cannot communicate with us on your behalf.

This vulnerability will be published if we do not receive a response to this report with 14 days.


2015-07-31: Discovered
2015-08-05: Reported to vendor via web form on http://web-profile.com.ua/feedback/
2015-08-06: Vendor responded
2015-08-10: Vendor reported fixed in version 4.0 but this does not address the issue: the plugin is still vulnerable.
2015-08-10: Published

Discovered by dxw:
Tom Adams
Please visit security.dxw.com for more information.

Quelle: Packet storm Security