This vulnerability was a potential CSRF attack. When running the Firebase emulator suite, there is an export endpoint that is used normally to export data from running emulators. If a user was running the emulator and navigated to a malicious website with the exploit on a browser that allowed calls to localhost (ie Chrome before v94), the website could exfiltrate emulator data. We recommend upgrading past version 13.6.0 or commit 068a2b08dc308c7ab4b569617f5fc8821237e3a0 https://github.com/firebase/firebase-tools/commit/068a2b08dc308c7ab4b569617f5fc8821237e3a0
Weakness
The web application does not, or cannot, sufficiently verify whether a request was intentionally provided by the user who sent the request, which could have originated from an unauthorized actor.
Affected Software
| Name |
Vendor |
Start Version |
End Version |
| Firebase_command_line_interface |
Google |
* |
13.6.0 (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 [REF-1482].
- 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