# CVE-2024-39906: Remote code execution in Haven IndieAuthClient (GHSL-2024-093)

> An attacker can execute arbitrary commands by tricking a logged-in administrator into clicking a crafted link in the Haven blog application.

- **Severity:** High 8.4 (`CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** No
- **Published:** 19 Jul 2024
- **Updated:** 2 Aug 2024
- **Also known as:** GHSA-65cm-7g24-hm9f

## What is CVE-2024-39906?

CVE-2024-39906 is a high-severity command injection vulnerability in havenweb haven, published on 19 Jul 2024. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

### Official description

A command injection vulnerability was found in the IndieAuth functionality of the Ruby on Rails based Haven blog web application. The affected functionality requires authentication, but an attacker can craft a link that they can pass to a logged in administrator of the blog software. This leads to the immediate execution of the provided commands when the link is accessed by the authenticated administrator. This issue may lead to Remote Code Execution (RCE) and has been addressed by commit `c52f07c`. Users are advised to upgrade. There are no known workarounds for this vulnerability.

Weakness: CWE-74 (Improper Neutralization of Special Elements in Output Used by a Downstream Component)

## Which versions are affected by CVE-2024-39906?


## How do I fix CVE-2024-39906?

No fix has been published for CVE-2024-39906 yet. Limit exposure of the affected software until one is available.

## Is CVE-2024-39906 being exploited?

There is no known exploitation of CVE-2024-39906 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2024-39906 and fix it if it is affected.

What it is: CVE-2024-39906 is a high-severity command injection vulnerability in havenweb haven, published on 19 Jul 2024. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2024-39906 in the wild and no public exploit code.

Affected product: havenweb haven. 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-2024-39906/ (Markdown: https://insights.sbomify.com/CVE-2024-39906/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2024-39906
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2024-39906
- OSV: https://osv.dev/vulnerability/CVE-2024-39906

---
From sbomify Insights: https://insights.sbomify.com/CVE-2024-39906/
Summaries are generated and may contain mistakes; the official description above is the record.