# What is CVE-2023-36476?

> CVE-2023-36476 is a medium-severity flaw (CVSS 5.5) in Calamares-Nixos-Extensions from Nixos, published on 29 June 2023. It is not on the list of flaws known to be exploited today. The latest forecast puts its chance of use in the next 30 days at 0.3%. If you run an affected version, plan in the vendor’s fix.

Canonical page: https://www.precursorintelligence.com/what-is/cve-2023-36476

## At a glance

- **Verdict:** Plan it in. No sign of exploitation and a low forecast. Patch it in your normal update cycle.
- **Precursor Intelligence risk score:** 46 out of 100 (Medium); action: Plan remediation. Kept up to date as the evidence changes.
- **Severity:** Medium (CVSS 5.5 out of 10)
- **Known to be exploited:** No, not on the list of flaws known to be exploited today
- **Chance of use in the next 30 days:** 0.3% (latest exploit-likelihood forecast)
- **Published:** 29 June 2023
- **Record last updated:** 7 July 2023
- **Main product:** Calamares-Nixos-Extensions from Nixos
- **Affected products:** 1

## What is CVE-2023-36476? In plain terms

An attacker has to be already on the device with an ordinary user account, and nobody has to click anything. If it works, the attacker can read data.

### The official description

calamares-nixos-extensions provides Calamares branding and modules for NixOS, a distribution of GNU/Linux. Users of calamares-nixos-extensions version 0.3.12 and prior who installed NixOS through the graphical calamares installer, with an unencrypted `/boot`, on either non-UEFI systems or with a LUKS partition different from `/` have their LUKS key file in `/boot` as a plaintext CPIO archive attached to their NixOS initrd. A patch is available and anticipated to be part of version 0.3.13 to backport to NixOS 22.11, 23.05, and unstable channels. Expert users who have a copy of their data may, as a workaround, re-encrypt the LUKS partition(s) themselves.

### What kind of flaw is it?

- CWE-200: Exposure of Sensitive Information to an Unauthorized Actor
- CWE-522: Insufficiently Protected Credentials

### How an attack on it works

- Where an attacker can be: Already on the device
- How hard it is to pull off: Easy: no special conditions
- Login needed first: An ordinary user account
- Does someone have to click: No, nobody has to do anything
- What an attacker gets: Can read data

Severity vector: `CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N`

## Is CVE-2023-36476 being exploited? Not that we know of

It is not on the list of flaws known to be exploited today. The latest forecast puts the chance of it being used in the next 30 days at 0.3%. That can change at any time, which is why we keep watching.

Exploit likelihood over the last 7 days: 0.3%, 0.3%, 0.3%, 0.3%, 0.3%, 0.3%, 0.3%.

### Timeline

- 29 June 2023: Published
- 7 July 2023: Record last updated

### How Precursor Intelligence ranks it

CVE-2023-36476 scores **46 out of 100 (Medium)**, with the action "Plan remediation".

Every published flaw gets a risk score from 0 to 100, kept up to date as the evidence changes. Four things go into the score, from the one that counts most to the ones that count less:

- Evidence it is being exploited: biggest factor
- How severe it is: strong factor
- How widely exposed it is: smaller factor
- Threat activity around it: smaller factor

85 and above is Critical. Anything confirmed as exploited is always marked for an emergency patch, whatever its score. When this flaw matches software you track, it lands in your list with its score and the reasons behind it.

## Who is affected by CVE-2023-36476?

The published record lists 1 product. Versions are as published: "before 0.3.13" means every version up to, but not including, 0.3.13.

- [Calamares-Nixos-Extensions](https://www.precursorintelligence.com/product/nixos/calamares-nixos-extensions) by [Nixos](https://www.precursorintelligence.com/vendors/nixos) (Application): before 0.3.13

## How do I fix CVE-2023-36476?

1. **Check whether you run it.** Compare your versions with the affected products above. Not sure what you run? Precursor Intelligence can work it out from your public website, or you can pick it from a list.
2. **Apply the vendor’s fix.** Install the update named in the vendor’s advisory. We’ve put the advisories and patch notes first in the list.
3. **If you can’t patch today.** Follow any mitigation the vendor publishes, and limit who can reach the affected system from the internet until the update is in.
4. **Keep an eye on it.** Track the product and we tell you as soon as we spot this flaw on the list of exploited flaws, or a jump in its exploit likelihood.

### References

- [github.com](https://github.com/vlinkz/calamares-nixos-extensions/commit/837ca4da5521a74d3b5ca6f7b88890a6713faa22) (Patch)
- [github.com](https://github.com/NixOS/calamares-nixos-extensions/security/advisories/GHSA-3rvf-24q2-24ww) (Mitigation, Vendor advisory)
- [github.com](https://github.com/osresearch/heads/issues/1348) (Exploit, Issue tracking)

## Questions

### What is CVE-2023-36476?

CVE-2023-36476 is a medium-severity flaw in Calamares-Nixos-Extensions from Nixos, published on 29 June 2023. An attacker has to be already on the device with an ordinary user account, and nobody has to click anything. If it works, the attacker can read data.

### How serious is CVE-2023-36476?

It scores 5.5 out of 10 on the CVSS severity scale, which is medium. Our risk score for CVE-2023-36476 is 46 out of 100, which is Medium. Its action is "Plan remediation". No sign of exploitation and a low forecast. Patch it in your normal update cycle.

### Is CVE-2023-36476 being exploited?

It is not on the list of flaws known to be exploited today. The latest forecast puts the chance of it being used in the next 30 days at 0.3%. That can change at any time, which is why we keep watching.

### Which versions does CVE-2023-36476 affect?

For Calamares-Nixos-Extensions from Nixos: before 0.3.13.

### How do I fix CVE-2023-36476?

Install the update the vendor names in its advisory, linked first under "How do I fix" on this page. If you can't patch today, follow the vendor's mitigation and limit who can reach the affected system from the internet.

## Does CVE-2023-36476 affect you?

Precursor Intelligence keeps checking for you:

- **Tell us what you run.** Pick your software from a list, or let us work it out from your website.
- **We match it to every flaw.** Over 400,000 published flaws, checked against your list.
- **Ranked by real-world risk.** Every flaw gets a 0 to 100 risk score, kept up to date, led by evidence criminals are using it.
- **Told as soon as we know.** An alert by email, in the app or by webhook to your own tools.

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