# CVE-2023-4612: MFA bypass in Apereo CAS

> Attackers can bypass Multi-Factor Authentication in Apereo CAS due to improper handling of remote address information.

- **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:** 9 Nov 2023
- **Updated:** 26 Feb 2025
- **Also known as:** GHSA-fxgj-cfm7-w8hw

## What is CVE-2023-4612?

CVE-2023-4612 is a critical authentication bypass vulnerability in Apereo Foundation CAS, published on 9 Nov 2023. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Improper Authentication vulnerability in Apereo CAS in jakarta.servlet.http.HttpServletRequest.getRemoteAddr method allows Multi-Factor Authentication bypass.This issue affects CAS: through 7.0.0-RC7. It is unknown whether in new versions the issue will be fixed. For the date of publication there is no patch, and the vendor does not treat it as a vulnerability.

Weakness: CWE-287 (Improper Authentication), CWE-302 (Authentication Bypass by Assumed-Immutable Data)

## Which versions are affected by CVE-2023-4612?

It affects 1 product.


Products: Apereo Central Authentication Service.

## How do I fix CVE-2023-4612?

No fix has been published for CVE-2023-4612 yet. Limit exposure of the affected software until one is available.

## Is CVE-2023-4612 being exploited?

There is no known exploitation of CVE-2023-4612 in the wild and no public exploit code.

## Other vulnerabilities in Apereo Foundation CAS

- [CVE-2024-4399](https://insights.sbomify.com/CVE-2024-4399/): CAS <= 1.0.0 - Unauthenticated SSRF (critical 9.1)
- [CVE-2019-10754](https://insights.sbomify.com/CVE-2019-10754/): Use of Insufficiently Random Values in Apereo CAS (high 8.1)
- [CVE-2020-27178](https://insights.sbomify.com/CVE-2020-27178/): Improper Authentication in Apereo CAS (high 7.5)
- [CVE-2015-1169](https://insights.sbomify.com/CVE-2015-1169/): Auth bypass in n/a (high 7.5)
- [CVE-2024-11208](https://insights.sbomify.com/CVE-2024-11208/): Apereo CAS login session expiration (medium 6.3)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2023-4612 and fix it if it is affected.

What it is: CVE-2023-4612 is a critical authentication bypass vulnerability in Apereo Foundation CAS, published on 9 Nov 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-2023-4612 in the wild and no public exploit code.

Affected product: Apereo Foundation CAS. 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-2023-4612/ (Markdown: https://insights.sbomify.com/CVE-2023-4612/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2023-4612
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-4612
- OSV: https://osv.dev/vulnerability/CVE-2023-4612

---
From sbomify Insights: https://insights.sbomify.com/CVE-2023-4612/
Summaries are generated and may contain mistakes; the official description above is the record.