GNU Mailman before 2.1.35 may allow remote Privilege Escalation. A csrf_token value is not specific to a single user account. An attacker can obtain a value within the context of an unprivileged user account, and then use that value in a CSRF attack against an admin (e.g., for account takeover).
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 |
| Mailman |
Gnu |
* |
2.1.35 (excluding) |
| Mailman |
Ubuntu |
bionic |
* |
| Mailman |
Ubuntu |
esm-infra/xenial |
* |
| Mailman |
Ubuntu |
focal |
* |
| Mailman |
Ubuntu |
upstream |
* |
| Red Hat Enterprise Linux 7 |
RedHat |
mailman-3:2.1.15-30.el7_9.2 |
* |
| Red Hat Enterprise Linux 8 |
RedHat |
mailman:2.1-8050020211109091611.aa3ced04 |
* |
| Red Hat Enterprise Linux 8.1 Extended Update Support |
RedHat |
mailman:2.1-8010020211110115755.656b880e |
* |
| Red Hat Enterprise Linux 8.2 Extended Update Support |
RedHat |
mailman:2.1-8020020211110111201.c3a0935b |
* |
| Red Hat Enterprise Linux 8.4 Extended Update Support |
RedHat |
mailman:2.1-8040020211109094506.70584597 |
* |
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