Description

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.

Classification

CVE ID: CVE-2023-3326

CVSS Base Severity: LOW

CVSS Base Score: 0.0

Affected Products

Vendor: FreeBSD

Product: FreeBSD

Exploit Prediction Scoring System (EPSS)

EPSS Score: 0.26% (probability of being exploited)

EPSS Percentile: 65.08% (scored less or equal to compared to others)

EPSS Date: 2025-02-03 (when was this score calculated)

References

https://security.FreeBSD.org/advisories/FreeBSD-SA-23:04.pam_krb5.asc
https://security.netapp.com/advisory/ntap-20230714-0005/
https://security.FreeBSD.org/advisories/FreeBSD-SA-23:09.pam_krb5.asc

Timeline