CVE-2023-3326 | Network authentication attack via pam_krb5

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.

Published: 2023-06-22 Last update: 2026-06-17 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2023-3326 is rated Moderate Risk (60.9/100): CVSS Critical severity, with medium exploitation likelihood (EPSS 1.10%). Review affected assets and schedule remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2023-3326

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-22 0.89% 1.10% +0.21%
2 2026-06-15 0.50% 0.89% +0.39%
3 2026-04-23 — 0.50% —

Full EPSS history (20 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2023-3326

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
9.8 3.1 CRITICAL
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 3.9 5.9 [email protected]

Weakness enumeration for CVE-2023-3326

OS Trackers for CVE-2023-3326

vendor priority summary link
debian unimportant CVE-2023-3326 unimportant priority: Debian including 1 source packages (libpam-krb5), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): open 5. https://security-tracker.debian.org/tracker/CVE-2023-3326
suse high CVE-2023-3326 severity important: SUSE including 31 source package names (libipa_hbac-devel, libipa_hbac0, …), 693 product×package rows across 39 product lines (SUSE CaaS Platform 4.0, SUSE Enterprise Storage 7, … (39 product lines)): Known Not Affected 693. https://www.suse.com/security/cve/CVE-2023-3326/
ubuntu low CVE-2023-3326 low priority: Ubuntu including 2 source packages (libpam-krb5, sssd), 26 status rows across 13 suites (bionic, focal, jammy, kinetic, lunar, mantic, noble, oracular, plucky, questing, trusty, upstream, xenial): deferred 13, ignored 11, needs-triage 2. https://ubuntu.com/security/CVE-2023-3326

Affected software / configurations for CVE-2023-3326

Vendor Product Version Raw CPE
freebsd freebsd < 12.4 cpe:2.3:o:freebsd:freebsd:*:*:*:*:*:*:*:*
freebsd freebsd >= 13.0, < 13.1 cpe:2.3:o:freebsd:freebsd:*:*:*:*:*:*:*:*
freebsd freebsd 12.4 cpe:2.3:o:freebsd:freebsd:12.4:-:*:*:*:*:*:*
freebsd freebsd 12.4 cpe:2.3:o:freebsd:freebsd:12.4:p1:*:*:*:*:*:*
freebsd freebsd 12.4 cpe:2.3:o:freebsd:freebsd:12.4:p2:*:*:*:*:*:*
freebsd freebsd 12.4 cpe:2.3:o:freebsd:freebsd:12.4:rc2-p1:*:*:*:*:*:*
freebsd freebsd 12.4 cpe:2.3:o:freebsd:freebsd:12.4:rc2-p2:*:*:*:*:*:*
freebsd freebsd 13.1 cpe:2.3:o:freebsd:freebsd:13.1:-:*:*:*:*:*:*
freebsd freebsd 13.1 cpe:2.3:o:freebsd:freebsd:13.1:b1-p1:*:*:*:*:*:*
freebsd freebsd 13.1 cpe:2.3:o:freebsd:freebsd:13.1:b2-p2:*:*:*:*:*:*
freebsd freebsd 13.1 cpe:2.3:o:freebsd:freebsd:13.1:p1:*:*:*:*:*:*
freebsd freebsd 13.1 cpe:2.3:o:freebsd:freebsd:13.1:p2:*:*:*:*:*:*
freebsd freebsd 13.1 cpe:2.3:o:freebsd:freebsd:13.1:p3:*:*:*:*:*:*
freebsd freebsd 13.1 cpe:2.3:o:freebsd:freebsd:13.1:p4:*:*:*:*:*:*
freebsd freebsd 13.1 cpe:2.3:o:freebsd:freebsd:13.1:p5:*:*:*:*:*:*
freebsd freebsd 13.1 cpe:2.3:o:freebsd:freebsd:13.1:p6:*:*:*:*:*:*
freebsd freebsd 13.1 cpe:2.3:o:freebsd:freebsd:13.1:p7:*:*:*:*:*:*
freebsd freebsd 13.1 cpe:2.3:o:freebsd:freebsd:13.1:rc1-p1:*:*:*:*:*:*
freebsd freebsd 13.2 cpe:2.3:o:freebsd:freebsd:13.2:-:*:*:*:*:*:*

References for CVE-2023-3326

cvelogic Threat Intelligence