# CVE-2021-21246: Pre-Auth Access token leak

> Attackers can retrieve arbitrary user access tokens via an unprotected REST endpoint, enabling impersonation and unauthorized access to projects.

- **Severity:** High 8.6 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 15 Jan 2021
- **Updated:** 3 Aug 2024
- **Also known as:** GHSA-66v7-gg85-f4gx

## What is CVE-2021-21246?

CVE-2021-21246 is a high-severity missing authorization vulnerability in theonedev onedev, published on 15 Jan 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

OneDev is an all-in-one devops platform. In OneDev before version 4.0.3, the REST UserResource endpoint performs a security check to make sure that only administrators can list user details. However for the `/users/{id}` endpoint there are no security checks enforced so it is possible to retrieve arbitrary user details including their Access Tokens! These access tokens can be used to access the API or clone code in the build spec via the HTTP(S) protocol. It has permissions to all projects accessible by the user account. This issue may lead to `Sensitive data leak` and leak the Access Token which can be used to impersonate the administrator or any other users. This issue was addressed in 4.0.3 by removing user info from restful api.

Weakness: CWE-862 (Missing Authorization)

## Which versions are affected by CVE-2021-21246?

It affects 1 product.


Products: Onedev Project Onedev.

## How do I fix CVE-2021-21246?

No fix has been published for CVE-2021-21246 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-21246 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2021-21246 exists.

Public exploit code:

- OneDev < 4.0.3 - User Access Token Leak (nuclei): http/cves/2021/CVE-2021-21246.yaml

## Other vulnerabilities in theonedev onedev

- [CVE-2021-21242](https://insights.sbomify.com/CVE-2021-21242/): Pre-Auth Unsafe Deserialization on AttachmentUploadServet (critical 10.0)
- [CVE-2021-21243](https://insights.sbomify.com/CVE-2021-21243/): Pre-Auth Unsafe Deserialization on KubernetesResource (critical 10.0)
- [CVE-2021-21244](https://insights.sbomify.com/CVE-2021-21244/): Pre-Auth SSTI via Bean validation message tampering (critical 10.0)
- [CVE-2021-21245](https://insights.sbomify.com/CVE-2021-21245/): Pre-Auth Arbitrary File Upload (critical 10.0)
- [CVE-2022-39206](https://insights.sbomify.com/CVE-2022-39206/): CI/CD Docker Escape in OneDev (critical 9.9)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-21246 and fix it if it is affected.

What it is: CVE-2021-21246 is a high-severity missing authorization vulnerability in theonedev onedev, published on 15 Jan 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2021-21246 exists.

Affected product: theonedev onedev. 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-2021-21246/ (Markdown: https://insights.sbomify.com/CVE-2021-21246/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-21246
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-21246
- OSV: https://osv.dev/vulnerability/CVE-2021-21246

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-21246/
Summaries are generated and may contain mistakes; the official description above is the record.