WordPress iframe 3.0 Stored Cross Site Scripting
Posted on 13 August 2015
Details ================ 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) Description ================ Stored XSS in iframe allows less privileged users to do almost anything an admin can Vulnerability ================ 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)"] Mitigations ================ 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. Timeline ================ 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.
