# CVE-2023-46116: Remote Code Execution via insufficiently sanitized call to shell.openExternal

> Attackers can execute arbitrary code on victim computers by exploiting insufficient URL scheme validation in the Tutanota email client.

- **Severity:** Critical 9.3 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:N`)
- **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:** 15 Dec 2023
- **Updated:** 8 Oct 2024
- **Also known as:** GHSA-mxgj-pq62-f644

## What is CVE-2023-46116?

CVE-2023-46116 is a critical command injection vulnerability in tutao tutanota, published on 15 Dec 2023. 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

Tutanota (Tuta Mail) is an encrypted email provider. Tutanota allows users to open links in emails in external applications. Prior to version 3.118.12, it correctly blocks the `file:` URL scheme, which can be used by malicious actors to gain code execution on a victims computer, however fails to check other harmful schemes such as `ftp:`, `smb:`, etc. which can also be used. Successful exploitation of this vulnerability will enable an attacker to gain code execution on a victim's computer. Version 3.118.2 contains a patch for this issue.

Weakness: CWE-20 (Improper Input Validation)

## Which versions are affected by CVE-2023-46116?

It affects 1 product.


Products: Tuta Tutanota.

## How do I fix CVE-2023-46116?

No fix has been published for CVE-2023-46116 yet. Limit exposure of the affected software until one is available.

## Is CVE-2023-46116 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2023-46116 exists.

## Other vulnerabilities in tutao tutanota

- [CVE-2024-23655](https://insights.sbomify.com/CVE-2024-23655/): Attacker can prevent users from accessing received emails (high 7.5)
- [CVE-2024-23330](https://insights.sbomify.com/CVE-2024-23330/): Tuta loads images from external resources (medium 5.3)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2023-46116 and fix it if it is affected.

What it is: CVE-2023-46116 is a critical command injection vulnerability in tutao tutanota, published on 15 Dec 2023. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2023-46116 exists.

Affected product: tutao tutanota. 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-2023-46116/ (Markdown: https://insights.sbomify.com/CVE-2023-46116/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2023-46116
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-46116
- OSV: https://osv.dev/vulnerability/CVE-2023-46116

---
From sbomify Insights: https://insights.sbomify.com/CVE-2023-46116/
Summaries are generated and may contain mistakes; the official description above is the record.