This affects the package com.softwaremill.akka-http-session:core_2.12 from 0 and before 0.6.1; all versions of package com.softwaremill.akka-http-session:core_2.11; the package com.softwaremill.akka-http-session:core_2.13 from 0 and before 0.6.1. CSRF protection can be bypassed by forging a request that contains the same value for both the X-XSRF-TOKEN header and the XSRF-TOKEN cookie value, as the check in randomTokenCsrfProtection only checks that the two values are equal and non-empty.
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.
Affected Software
| Name |
Vendor |
Start Version |
End Version |
| Akka-http-session |
Softwaremill |
* |
0.6.1 (excluding) |
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