# CVE-2023-3326: Network authentication attack via pam_krb5

> Attackers can bypass authentication in FreeBSD using pam_krb5 without a keytab by controlling KDC responses, allowing unauthorized access to any user account.

- **Severity:** Critical 9.8 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 22 Jun 2023
- **Updated:** 5 Dec 2024
- **Also known as:** DEBIAN-CVE-2023-3326, GHSA-vjhp-527w-c5vj, UBUNTU-CVE-2023-3326

## What is CVE-2023-3326?

CVE-2023-3326 is a critical authentication bypass vulnerability in Freebsd Freebsd, published on 22 Jun 2023. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official 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.

Weakness: CWE-287 (Improper Authentication), CWE-303 (Incorrect Implementation of Authentication Algorithm)

## Which versions are affected by CVE-2023-3326?

It affects 1 product.


Products: Freebsd Freebsd.

## How do I fix CVE-2023-3326?

No fix has been published for CVE-2023-3326 yet. Limit exposure of the affected software until one is available.

## Is CVE-2023-3326 being exploited?

There is no known exploitation of CVE-2023-3326 in the wild and no public exploit code.

## Other vulnerabilities in Freebsd Freebsd

- [CVE-2018-17160](https://insights.sbomify.com/CVE-2018-17160/): Memory corruption in FreeBSD (critical 10.0)
- [CVE-2014-3954](https://insights.sbomify.com/CVE-2014-3954/): Memory corruption in n/a (critical 10.0)
- [CVE-2006-4304](https://insights.sbomify.com/CVE-2006-4304/): Memory corruption in n/a (critical 10.0)
- [CVE-2006-0226](https://insights.sbomify.com/CVE-2006-0226/): Integer overflow in n/a (critical 10.0)
- [CVE-2004-0002](https://insights.sbomify.com/CVE-2004-0002/): Denial of service in n/a (critical 10.0)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2023-3326 and fix it if it is affected.

What it is: CVE-2023-3326 is a critical authentication bypass vulnerability in Freebsd Freebsd, published on 22 Jun 2023. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2023-3326 in the wild and no public exploit code.

Affected product: Freebsd Freebsd. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2023-3326/ (Markdown: https://insights.sbomify.com/CVE-2023-3326/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2023-3326
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-3326
- OSV: https://osv.dev/vulnerability/CVE-2023-3326

---
From sbomify Insights: https://insights.sbomify.com/CVE-2023-3326/
Summaries are generated and may contain mistakes; the official description above is the record.