Cross-site request forgery (CSRF) vulnerability in multiple Century Systems routers including XR-410 before 1.6.9, XR-510 before 3.5.3, XR-440 before 1.7.8, and other XR series routers from XR-510 to XR-730 allows remote attackers to modify configuration as the administrator via unknown vectors.
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 |
| Xr-1100 |
Centurysys |
* |
1.6.2 (including) |
| Xr-410 |
Centurysys |
* |
1.6.8 (including) |
| Xr-410-l2 |
Centurysys |
* |
1.6.1 (including) |
| Xr-440 |
Centurysys |
* |
1.7.7 (including) |
| Xr-510 |
Centurysys |
* |
3.5.0 (including) |
| Xr-540 |
Centurysys |
* |
3.5.2 (including) |
| Xr-640 |
Centurysys |
* |
1.6.7 (including) |
| Xr-640-l2 |
Centurysys |
* |
1.6.1 (including) |
| Xr-730 |
Centurysys |
* |
3.5.0 (including) |
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