# CVE-2020-27839: Information disclosure in ceph-dashboard

> Storing JWTs in localStorage exposes Ceph dashboard users to token theft via XSS, compromising data confidentiality and integrity.

- **Severity:** Medium 5.4 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** Yes
- **Published:** 26 May 2021
- **Updated:** 4 Aug 2024
- **Also known as:** DEBIAN-CVE-2020-27839, GHSA-2c8x-3ppx-9gj3, UBUNTU-CVE-2020-27839

## What is CVE-2020-27839?

CVE-2020-27839 is a medium-severity vulnerability in ceph-dashboard, published on 26 May 2021. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.

### Official description

A flaw was found in ceph-dashboard. The JSON Web Token (JWT) used for user authentication is stored by the frontend application in the browser’s localStorage which is potentially vulnerable to attackers via XSS attacks. The highest threat from this vulnerability is to data confidentiality and integrity.

Weakness: CWE-522 (Insufficiently Protected Credentials)

## Which versions are affected by CVE-2020-27839?

It affects 1 product.


Products: Redhat Ceph.

## How do I fix CVE-2020-27839?

Apply the vendor's patch.

## Is CVE-2020-27839 being exploited?

There is no known exploitation of CVE-2020-27839 in the wild and no public exploit code.

## Other vulnerabilities in ceph-dashboard

- [CVE-2022-3650](https://insights.sbomify.com/CVE-2022-3650/): Privilege escalation in Ceph (high 7.8)
- [CVE-2024-47866](https://insights.sbomify.com/CVE-2024-47866/): RGW DoS attack with empty HTTP header in S3 object copy (high 7.5)
- [CVE-2016-8626](https://insights.sbomify.com/CVE-2016-8626/): Denial of service in Ceph (medium 6.5)
- [CVE-2016-5009](https://insights.sbomify.com/CVE-2016-5009/): Denial of service in n/a (medium 6.5)
- [CVE-2018-16889](https://insights.sbomify.com/CVE-2018-16889/): Information disclosure in ceph (medium 5.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2020-27839 and fix it if it is affected.

What it is: CVE-2020-27839 is a medium-severity vulnerability in ceph-dashboard, published on 26 May 2021. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2020-27839 in the wild and no public exploit code.

Affected product: ceph-dashboard. 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-2020-27839/ (Markdown: https://insights.sbomify.com/CVE-2020-27839/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2020-27839
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-27839
- OSV: https://osv.dev/vulnerability/CVE-2020-27839

---
From sbomify Insights: https://insights.sbomify.com/CVE-2020-27839/
Summaries are generated and may contain mistakes; the official description above is the record.