# CVE-2023-45140: Group-based JIT MFA bypass on scp and sftp in The Bastion

> Attackers can bypass group-based JIT MFA when using SCP or SFTP through The Bastion, gaining unauthorized access without the required second factor.

- **Severity:** Medium 4.8 (`CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** An administrator
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** No
- **Published:** 8 Nov 2023
- **Updated:** 12 Sep 2024
- **Also known as:** GHSA-pr4q-w883-pf5x

## What is CVE-2023-45140?

CVE-2023-45140 is a medium-severity authentication bypass vulnerability in ovh the-bastion, published on 8 Nov 2023. An attacker needs administrator access to exploit it, and only if a user opens a file or follows a link.

### Official description

The Bastion provides authentication, authorization, traceability and auditability for SSH accesses. SCP and SFTP plugins don't honor group-based JIT MFA. Establishing a SCP/SFTP connection through The Bastion via a group access where MFA is enforced does not ask for additional factor. This abnormal behavior only applies to per-group-based JIT MFA. Other MFA setup types, such as Immediate MFA, JIT MFA on a per-plugin basis and JIT MFA on a per-account basis are not affected. This issue has been patched in version 3.14.15.

Weakness: CWE-306 (Missing Authentication for Critical Functionality)

## Which versions are affected by CVE-2023-45140?

It affects 1 product.


Products: Ovh The-Bastion.

## How do I fix CVE-2023-45140?

No fix has been published for CVE-2023-45140 yet. Limit exposure of the affected software until one is available.

## Is CVE-2023-45140 being exploited?

There is no known exploitation of CVE-2023-45140 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2023-45140 and fix it if it is affected.

What it is: CVE-2023-45140 is a medium-severity authentication bypass vulnerability in ovh the-bastion, published on 8 Nov 2023. An attacker needs administrator access to exploit it, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2023-45140 in the wild and no public exploit code.

Affected product: ovh the-bastion. 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-2023-45140/ (Markdown: https://insights.sbomify.com/CVE-2023-45140/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2023-45140
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-45140
- OSV: https://osv.dev/vulnerability/CVE-2023-45140

---
From sbomify Insights: https://insights.sbomify.com/CVE-2023-45140/
Summaries are generated and may contain mistakes; the official description above is the record.