CVE-2023-3326
Network authentication attack via pam_krb5
- Published
- Updated
- Reserved
- Assigned by
- freebsd
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.
Timeline
ID reserved
By freebsd
- 3 days later
· 3 days later
Published
- 18 months later
· 18 months later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| NVDNVD · Modified | 3.1 | Critical9.8 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
- EPSS (exploitation in 30 days)
- 1.1% · top 34% of all CVEs (7 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: yes · Technical impact: total
The list uses the assigner's score when there is one, then CISA's, then NVD's: Critical 9.8.
Weakness
Affected products
What to do
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.
References (3)
- https://security.FreeBSD.org/advisories/FreeBSD-SA-23:04.pam_krb5.asc (opens in a new tab)vendor-advisoryx_transferred
- https://security.netapp.com/advisory/ntap-20230714-0005/ (opens in a new tab)third-party-advisoryx_transferred
- https://security.FreeBSD.org/advisories/FreeBSD-SA-23:09.pam_krb5.asc (opens in a new tab)vendor-advisoryx_transferred
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://trackcve.app/cve/CVE-2023-3326)Record last updated .