# CVE-2023-37266: Weak json web token (JWT) secrets in CasaOS

> Unauthenticated attackers can forge JWTs to bypass authentication and execute arbitrary commands as root on CasaOS instances.

- **Severity:** Critical 9.8 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 17 Jul 2023
- **Updated:** 12 Dec 2024
- **Also known as:** GHSA-m5q5-8mfw-p2hr, GO-2023-1931

## What is CVE-2023-37266?

CVE-2023-37266 is a critical vulnerability in IceWhaleTech CasaOS, published on 17 Jul 2023. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

CasaOS is an open-source Personal Cloud system. Unauthenticated attackers can craft arbitrary JWTs and access features that usually require authentication and execute arbitrary commands as `root` on CasaOS instances. This problem was addressed by improving the validation of JWTs in commit `705bf1f`. This patch is part of CasaOS 0.4.4. Users should upgrade to CasaOS 0.4.4. If they can't, they should temporarily restrict access to CasaOS to untrusted users, for instance by not exposing it publicly.

Weakness: CWE-287 (Improper Authentication)

## Which versions are affected by CVE-2023-37266?

3 open source packages ship an affected version, including github.com/IceWhaleTech/CasaOS. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `github.com/IceWhaleTech/CasaOS` | Go | All versions | 0.4.4 |
| `github.com/IceWhaleTech/CasaOS` | Go | All versions | 0.4.4 |
| `github.com/IceWhaleTech/CasaOS` | Go | All versions | 0.4.4 |

Products: Icewhale Casaos.

## How do I fix CVE-2023-37266?

Upgrade github.com/IceWhaleTech/CasaOS to 0.4.4 or later.

## Is CVE-2023-37266 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2023-37266 exists.

Public exploit code:

- CasaOS  < 0.4.4 - Authentication Bypass via Random JWT Token (nuclei): http/cves/2023/CVE-2023-37266.yaml

## Other vulnerabilities in IceWhaleTech CasaOS

- [CVE-2023-37265](https://insights.sbomify.com/CVE-2023-37265/): Incorrect identification of source IP addresses in CasaOS (critical 9.8)
- [CVE-2022-24193](https://insights.sbomify.com/CVE-2022-24193/): Command Injection in CasaOS (critical 9.8)
- [CVE-2024-24767](https://insights.sbomify.com/CVE-2024-24767/): CasaOS Improper Restriction of Excessive Authentication Attempts vulnerability (critical 9.1)
- [CVE-2023-37469](https://insights.sbomify.com/CVE-2023-37469/): CasaOS Command Injection vulnerability (high 8.8)
- [CVE-2024-24765](https://insights.sbomify.com/CVE-2024-24765/): CasaOS-UserService allows unauthorized access to any file (high 7.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2023-37266 and fix it if it is affected.

What it is: CVE-2023-37266 is a critical vulnerability in IceWhaleTech CasaOS, published on 17 Jul 2023. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2023-37266 exists.

Affected packages and fixed versions:
- github.com/IceWhaleTech/CasaOS (Go): affected all versions; fixed in 0.4.4
- github.com/IceWhaleTech/CasaOS (Go): affected all versions; fixed in 0.4.4
- github.com/IceWhaleTech/CasaOS (Go): affected all versions; fixed in 0.4.4

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-2023-37266/ (Markdown: https://insights.sbomify.com/CVE-2023-37266/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2023-37266
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-37266
- OSV: https://osv.dev/vulnerability/CVE-2023-37266

---
From sbomify Insights: https://insights.sbomify.com/CVE-2023-37266/
Summaries are generated and may contain mistakes; the official description above is the record.