Zero-Day Advisory

Fortinet Discovers Plone Login Form Cross-Site Scripting Vulnerability


Fortinet's FortiGuard Labs has discovered a Cross-Site Scripting vulnerability in Plone.

Plone is among the top 2% of all open source projects worldwide. It has more than 103,000 commits by nearly 900 code contributors. Plone is supported by more than 350 solution providers in more than 100 countries. The project has been actively developed since 2001, is available in more than 40 languages, and has the best security track record of any major CMS.

A Cross-Site Scripting vulnerability has been discovered in Plone. The vulnerability is caused by an error because the login 302 redirect function doesn't correctly process user-supplied data. An attacker might exploit this by letting you click on a specially crafted link. You would login, and get redirected to the site of the attacker, letting you think that you are still on the original Plone site. Or some Javascript code of the attacker could be executed within the context of victim's browser.


FortiGuard Labs released the following FortiGate IPS signature which covers this specific vulnerability:

Released Jan 20, 2017

FortiWeb can protect this specific vulnerability since the signature package 10.077.

Users should apply the solution provided by Plone.

Additional Information

Fortinet reported the vulnerability to Plone on Jan. 20, 2017.

Plone confirmed the vulnerability on Jan. 20, 2017.

Plone released patch for the vulnerability on Nov. 28, 2017.


This vulnerability was discovered by Zhouyuan Yang of Fortinet's FortiGuard Labs.

IPS Subscription

Fortinet customers who subscribe to Fortinet's intrusion prevention (IPS) service should be protected against this vulnerability with the appropriate configuration parameters in place. Fortinet's IPS service is one component of FortiGuard Subscription Services, which also offer comprehensive solutions such as antivirus, Web content filtering and antispam capabilities. These services enable protection against threats on both application and network layers. FortiGuard Services are continuously updated by FortiGuard Labs, which enables Fortinet to deliver a combination of multi-layered security intelligence and true zero-day protection from new and emerging threats. These updates are delivered to all FortiGate, FortiMail and FortiClient products. Fortinet strictly follows responsible disclosure guidelines to ensure optimum protection during a threat's lifecycle.