D-Link DCS cameras have a weak/insecure CrossDomain.XML file that allows sites hosting malicious Flash objects to access and/or change the devices settings via a CSRF attack. This is because of the allow-access-from domain child element set to *, thus accepting requests from any domain. If a victim logged into the cameras web console visits a malicious site hosting a malicious Flash file from another Browser tab, the malicious Flash file then can send requests to the victims DCS series Camera without knowing the credentials. An attacker can host a malicious Flash file that can retrieve Live Feeds or information from the victims DCS series Camera, add new admin users, or make other changes to the device. Known affected devices are DCS-933L with firmware before 1.13.05, DCS-5030L, DCS-5020L, DCS-2530L, DCS-2630L, DCS-930L, DCS-932L, and DCS-932LB1.
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 |
| Dcs-2230l_firmware |
Dlink |
* |
1.03.01 (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