# CVE-2021-20253: Privilege escalation in ansible-tower

> Attackers can escape job isolation to escalate privileges to the awx user, compromising data confidentiality, integrity, and system availability.

- **Severity:** Medium 6.7 (`CVSS:3.1/AV:L/AC:H/PR:L/UI:R/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Local or same network only
- **Victim action needed:** A user has to click or open something
- **Fix available:** No
- **Published:** 9 Mar 2021
- **Updated:** 3 Aug 2024
- **Also known as:** GHSA-rr45-4xhx-rxc8

## What is CVE-2021-20253?

CVE-2021-20253 is a medium-severity vulnerability in Redhat Ansible Tower, published on 9 Mar 2021. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.

### Official description

A flaw was found in ansible-tower. The default installation is vulnerable to Job Isolation escape allowing an attacker to elevate the privilege from a low privileged user to the awx user from outside the isolated environment. The highest threat from this vulnerability is to data confidentiality and integrity as well as system availability.

Weakness: CWE-552 (Files or Directories Accessible to External Parties)

## Which versions are affected by CVE-2021-20253?

It affects 1 product.


Products: Redhat Ansible Tower.

## How do I fix CVE-2021-20253?

No fix has been published for CVE-2021-20253 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-20253 being exploited?

There is no known exploitation of CVE-2021-20253 in the wild and no public exploit code.

Public exploit code:

- CVE-2021-20253: Privilege Escalation via Job Isolation Escape in Ansible Tower (github_poc): https://github.com/mbadanoiu/CVE-2021-20253

## Other vulnerabilities in Redhat Ansible Tower

- [CVE-2018-10884](https://insights.sbomify.com/CVE-2018-10884/): Cross-site request forgery in ansible-tower (high 8.8)
- [CVE-2018-1104](https://insights.sbomify.com/CVE-2018-1104/): Code injection in Ansible Tower (high 8.8)
- [CVE-2019-14890](https://insights.sbomify.com/CVE-2019-14890/): Information disclosure in Tower (high 8.4)
- [CVE-2017-12148](https://insights.sbomify.com/CVE-2017-12148/): Code injection in Ansible Tower (high 8.4)
- [CVE-2019-19340](https://insights.sbomify.com/CVE-2019-19340/): Misconfiguration in Tower (high 8.2)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-20253 and fix it if it is affected.

What it is: CVE-2021-20253 is a medium-severity vulnerability in Redhat Ansible Tower, published on 9 Mar 2021. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2021-20253 in the wild and no public exploit code.

Affected product: Redhat Ansible Tower. 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-2021-20253/ (Markdown: https://insights.sbomify.com/CVE-2021-20253/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-20253
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-20253
- OSV: https://osv.dev/vulnerability/CVE-2021-20253

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-20253/
Summaries are generated and may contain mistakes; the official description above is the record.