# CVE-2021-43833: Account takeover in eLabFTW


- **Severity:** High 8.1 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N`)
- **Exploited in the wild:** Not known
- **Fix available:** No
- **Published:** 15 Dec 2021
- **Updated:** 4 Aug 2024
- **Also known as:** GHSA-v659-q2fh-v99w

## What is CVE-2021-43833?

CVE-2021-43833 is a high-severity vulnerability in elabftw, published on 15 Dec 2021. 

### Official description

eLabFTW is an electronic lab notebook manager for research teams. In versions prior to 4.2.0 there is a vulnerability which allows any authenticated user to gain access to arbitrary accounts by setting a specially crafted email address. This vulnerability impacts all instances that have not set an explicit email domain name allowlist. Note that whereas neither administrators nor targeted users are notified of a change, an attacker will need to control an account. The default settings require administrators to validate newly created accounts. The problem has been patched. Users should upgrade to at least version 4.2.0. For users unable to upgrade enabling an email domain allow list (from Sysconfig panel, Security tab) will completely resolve the issue.

Weakness: CWE-287 (Improper Authentication)

## Which versions are affected by CVE-2021-43833?

It affects 1 product.


Products: Elabftw Elabftw.

## How do I fix CVE-2021-43833?

No fix has been published for CVE-2021-43833 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-43833 being exploited?

There is no known exploitation of CVE-2021-43833 in the wild and no public exploit code.

## Other vulnerabilities in elabftw

- [CVE-2021-43834](https://insights.sbomify.com/CVE-2021-43834/): Incorrect Authentication in elabftw (critical 9.1)
- [CVE-2024-28100](https://insights.sbomify.com/CVE-2024-28100/): Stored Cross-site Scripting leading to arbitrary actions taken on behalf of users in elabftw (high 8.9)
- [CVE-2019-12185](https://insights.sbomify.com/CVE-2019-12185/): File upload in n/a (high 8.8)
- [CVE-2024-25632](https://insights.sbomify.com/CVE-2024-25632/): Unauthorised granting of administrator privileges over arbitrary teams under certain circumstances (high 8.6)
- [CVE-2025-25206](https://insights.sbomify.com/CVE-2025-25206/): Incorrect input validation could allow an authenticated user to read sensitive information (high 8.3)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-43833 and fix it if it is affected.

What it is: CVE-2021-43833 is a high-severity vulnerability in elabftw, published on 15 Dec 2021. 
Exploitation: There is no known exploitation of CVE-2021-43833 in the wild and no public exploit code.

Affected product: elabftw. 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-2021-43833/ (Markdown: https://insights.sbomify.com/CVE-2021-43833/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-43833
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-43833
- OSV: https://osv.dev/vulnerability/CVE-2021-43833

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-43833/
Summaries are generated and may contain mistakes; the official description above is the record.