SkillTree is a micro-learning gamification platform. Prior to version 2.12.6, the endpoint
/admin/projects/{projectname}/skills/{skillname}/video (and probably others) is open to a cross-site request forgery (CSRF) vulnerability. Due to the endpoint being CSRFable e.g POST request, supports a content type that can be exploited (multipart file upload), makes a state change and has no CSRF mitigations in place (samesite flag, CSRF token). It is possible to perform a CSRF attack against a logged in admin account, allowing an attacker that can target a logged in admin of Skills Service to modify the videos, captions, and text of the skill. Version 2.12.6 contains a patch for this issue.
Weakness
The web application does not, or can not, sufficiently verify whether a well-formed, valid, consistent request was intentionally provided by the user who submitted the request.
Potential Mitigations
- Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid.
- For example, use anti-CSRF packages such as the OWASP CSRFGuard. [REF-330]
- Another example is the ESAPI Session Management control, which includes a component for CSRF. [REF-45]
- Use the “double-submitted cookie” method as described by Felten and Zeller:
- When a user visits a site, the site should generate a pseudorandom value and set it as a cookie on the user’s machine. The site should require every form submission to include this value as a form value and also as a cookie value. When a POST request is sent to the site, the request should only be considered valid if the form value and the cookie value are the same.
- Because of the same-origin policy, an attacker cannot read or modify the value stored in the cookie. To successfully submit a form on behalf of the user, the attacker would have to correctly guess the pseudorandom value. If the pseudorandom value is cryptographically strong, this will be prohibitively difficult.
- This technique requires Javascript, so it may not work for browsers that have Javascript disabled. [REF-331]
References