# CVE-2023-20903: Auth bypass in Cloud Foundry

> Attackers with valid refresh tokens from a deactivated identity provider can bypass authentication and access Cloud Foundry resources.

- **Severity:** Medium 4.3 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 28 Mar 2023
- **Updated:** 19 Feb 2025
- **Also known as:** GHSA-5rqc-wqwj-478f

## What is CVE-2023-20903?

CVE-2023-20903 is a medium-severity authentication bypass vulnerability in Cloud Foundry, published on 28 Mar 2023. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

This disclosure regards a vulnerability related to UAA refresh tokens and external identity providers.Assuming that an external identity provider is linked to the UAA, a refresh token is issued to a client on behalf of a user from that identity provider, the administrator of the UAA deactivates the identity provider from the UAA. It is expected that the UAA would reject a refresh token during a refresh token grant, but it does not (hence the vulnerability). It will continue to issue access tokens to request presenting such refresh tokens, as if the identity provider was still active. As a result, clients with refresh tokens issued through the deactivated identity provider would still have access to Cloud Foundry resources until their refresh token expires (which defaults to 30 days).

Weakness: CWE-613 (DEPRECATED: Insufficient Session Expiration)

## Which versions are affected by CVE-2023-20903?

It affects 1 product.


Products: Cloudfoundry User Account and Authentication.

## How do I fix CVE-2023-20903?

No fix has been published for CVE-2023-20903 yet. Limit exposure of the affected software until one is available.

## Is CVE-2023-20903 being exploited?

There is no known exploitation of CVE-2023-20903 in the wild and no public exploit code.

## Other vulnerabilities in Cloud Foundry

- [CVE-2019-11278](https://insights.sbomify.com/CVE-2019-11278/): Privilege Escalation via Blind SCIM Injection in UAA (high 8.7)
- [CVE-2019-11274](https://insights.sbomify.com/CVE-2019-11274/): UAA SCIM Filter XSS (medium 4.3)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2023-20903 and fix it if it is affected.

What it is: CVE-2023-20903 is a medium-severity authentication bypass vulnerability in Cloud Foundry, published on 28 Mar 2023. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2023-20903 in the wild and no public exploit code.

Affected product: Cloud Foundry. 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-2023-20903/ (Markdown: https://insights.sbomify.com/CVE-2023-20903/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2023-20903
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-20903
- OSV: https://osv.dev/vulnerability/CVE-2023-20903

---
From sbomify Insights: https://insights.sbomify.com/CVE-2023-20903/
Summaries are generated and may contain mistakes; the official description above is the record.