# ALEA-2021:5239: cloud-init bug fix and enhancement update

> Cloud-init fails to start or configure routes correctly after updates, potentially causing service disruption for cloud instances.

- **Severity:** Not scored
- **Exploited in the wild:** Not known
- **Login needed:** Not stated
- **Attackable:** Not stated
- **Victim action needed:** Not stated
- **Fix available:** Yes
- **Published:** 21 Dec 2021

## What is ALEA-2021:5239?

ALEA-2021:5239 is a vulnerability in cloud-init, published on 21 Dec 2021. 

### Official description

The cloud-init packages provide a set of init scripts for cloud instances.
Cloud instances need special scripts to run during initialization to
retrieve and install SSH keys, and to let the user run various scripts.

Bug Fix(es) and Enhancement(s):

* cloud-init.service fails to start after package update (BZ#2028738)

* [AlmaLinux-8] Above 19.2 of cloud-init fails to configure routes when
configuring static and default routes to the same destination IP
(BZ#2028756)

## Which versions are affected by ALEA-2021:5239?


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `cloud-init` | AlmaLinux:8 | All versions | 21.1-7.el8_5.3.alma |

## How do I fix ALEA-2021:5239?

Apply the vendor's patch.

## Is ALEA-2021:5239 being exploited?

There is no known exploitation of ALEA-2021:5239 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for ALEA-2021:5239 and fix it if it is affected.

What it is: ALEA-2021:5239 is a vulnerability in cloud-init, published on 21 Dec 2021. 
Exploitation: There is no known exploitation of ALEA-2021:5239 in the wild and no public exploit code.

Affected product: cloud-init. 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/ALEA-2021-5239/ (Markdown: https://insights.sbomify.com/ALEA-2021-5239/index.md)
```

## Sources

- OSV: https://osv.dev/vulnerability/ALEA-2021:5239

---
From sbomify Insights: https://insights.sbomify.com/ALEA-2021-5239/
Summaries are generated and may contain mistakes; the official description above is the record.