This article is a part of our Vulnerability Database (back to index)
Cross-Site Request Forgery occurrences in Firefox
POST requests made by NPAPI plugins, such as Flash, that receive a status 308 redirect response can bypass CORS requirements. This can allow an attacker to perform Cross-Site Request Forgery (CSRF) attacks. This vulnerability affects Firefox ESR < 60.8, Firefox < 68, and Thunderbird < 60.8. (2019-07-23, CVE-2019-11712)
In Reader View SameSite cookie protections are not checked on exiting. This allows for a payload to be triggered when Reader View is exited if loaded by a malicious site while Reader mode is active, bypassing CSRF protections. This vulnerability affects Firefox < 61. (2018-10-18, CVE-2018-12370)
NPAPI plugins, such as Adobe Flash, can send non-simple cross-origin requests, bypassing CORS by making a same-origin POST that does a 307 redirect to the target site. This allows for a malicious site to engage in cross-site request forgery (CSRF) attacks. This vulnerability affects Thunderbird < 60, Thunderbird < 52.9, Firefox ESR < 60.1, Firefox ESR < 52.9, and Firefox < 61. (2018-10-18, CVE-2018-12364)
Why Cross-Site Request Forgery can be dangerous
The absence of Anti-CSRF tokens may lead to a Cross-Site Request Forgery attack that can result in executing a specific application action as another logged in user, e.g. steal their account by changing their email and password or silently adding a new admin user account when executed from the administrator account.
The attacker may copy one of your web application forms, e.g. email/password change form.
The webpage will contain a form with the exact set of fields as the original application but with input values already provided and the submit button replaced with a Javascript code causing auto-submission. When the page is accessed the form will be immediately submitted and page contents replaced with a valid content or a redirect to your original application.
One of your application users who is already logged in can be then tricked to navigate to such malicious page e.g. by clicking a link in a phishing email, and the pre-populated form content will be submitted to your application like it would be submitted by your user.