pam_krb5 authenticates a user by essentially running kinit with the password, getting a ticket-granting ticket (tgt) from the Kerberos KDC (Key Distribution Center) over the network, as a way to verify the password. However, if a keytab is not provisioned on the system, pam_krb5 has no way to validate the response from the KDC, and essentially trusts the tgt provided over the network as being valid. In a non-default FreeBSD installation that leverages pam_krb5 for authentication and does not have a keytab provisioned, an attacker that is able to control both the password and the KDC responses can return a valid tgt, allowing authentication to occur for any user on the system.
When an actor claims to have a given identity, the product does not prove or insufficiently proves that the claim is correct.
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Freebsd | Freebsd | * | 12.4 (excluding) |
| Freebsd | Freebsd | 13.0 (including) | 13.1 (excluding) |
| Freebsd | Freebsd | 12.4 (including) | 12.4 (including) |
| Freebsd | Freebsd | 12.4-p1 (including) | 12.4-p1 (including) |
| Freebsd | Freebsd | 12.4-p2 (including) | 12.4-p2 (including) |
| Freebsd | Freebsd | 12.4-rc2-p1 (including) | 12.4-rc2-p1 (including) |
| Freebsd | Freebsd | 12.4-rc2-p2 (including) | 12.4-rc2-p2 (including) |
| Freebsd | Freebsd | 13.1 (including) | 13.1 (including) |
| Freebsd | Freebsd | 13.1-b1-p1 (including) | 13.1-b1-p1 (including) |
| Freebsd | Freebsd | 13.1-b2-p2 (including) | 13.1-b2-p2 (including) |
| Freebsd | Freebsd | 13.1-p1 (including) | 13.1-p1 (including) |
| Freebsd | Freebsd | 13.1-p2 (including) | 13.1-p2 (including) |
| Freebsd | Freebsd | 13.1-p3 (including) | 13.1-p3 (including) |
| Freebsd | Freebsd | 13.1-p4 (including) | 13.1-p4 (including) |
| Freebsd | Freebsd | 13.1-p5 (including) | 13.1-p5 (including) |
| Freebsd | Freebsd | 13.1-p6 (including) | 13.1-p6 (including) |
| Freebsd | Freebsd | 13.1-p7 (including) | 13.1-p7 (including) |
| Freebsd | Freebsd | 13.1-rc1-p1 (including) | 13.1-rc1-p1 (including) |
| Freebsd | Freebsd | 13.2 (including) | 13.2 (including) |
| Libpam-krb5 | Ubuntu | bionic | * |
| Libpam-krb5 | Ubuntu | kinetic | * |
| Libpam-krb5 | Ubuntu | lunar | * |
| Libpam-krb5 | Ubuntu | mantic | * |
| Libpam-krb5 | Ubuntu | trusty | * |
| Libpam-krb5 | Ubuntu | xenial | * |
| Sssd | Ubuntu | bionic | * |
| Sssd | Ubuntu | kinetic | * |
| Sssd | Ubuntu | lunar | * |
| Sssd | Ubuntu | mantic | * |
| Sssd | Ubuntu | trusty | * |
| Sssd | Ubuntu | xenial | * |