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.
Fixes

Solution

No solution given by the vendor.


Workaround

If you are not using Kerberos at all, ensure /etc/krb5.conf is missing from your system. Additionally, ensure pam_krb5 is commented out of your PAM configuration located as documented in pam.conf(5), generally /etc/pam.d. Note, the default FreeBSD PAM configuration has pam_krb5 commented out. If you are using Kerberos, but not using pam_krb5, ensure pam_krb5 is commented out of your PAM configuration located as documented in pam.conf(5), generally /etc/pam.d. Note, the default FreeBSD PAM configuration has pam_krb5 commented out. If you are using pam_krb5, ensure you have a keytab on your system as provided by your Kerberos administrator.

History

Thu, 05 Dec 2024 18:15:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}


cve-icon MITRE

Status: PUBLISHED

Assigner: freebsd

Published:

Updated: 2024-12-05T17:45:19.729Z

Reserved: 2023-06-19T16:14:36.133Z

Link: CVE-2023-3326

cve-icon Vulnrichment

Updated: 2024-08-02T06:55:03.226Z

cve-icon NVD

Status : Modified

Published: 2023-06-22T17:15:44.833

Modified: 2024-11-21T08:17:01.307

Link: CVE-2023-3326

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

No data.