# CVE-2023-33193: Emby Server Proxy Header Spoofing Vulnerability

> Attackers can bypass authentication and gain administrative access by spoofing proxy headers on publicly accessible Emby Servers with loose account settings.

- **Severity:** Critical 9.1 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 30 May 2023
- **Updated:** 10 Jan 2025

## What is CVE-2023-33193?

CVE-2023-33193 is a critical authentication bypass vulnerability in EmbySupport security, published on 30 May 2023. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Emby Server is a user-installable home media server which stores and organizes a user's media files of virtually any format and makes them available for viewing at home and abroad on a broad range of client devices. This vulnerability may allow administrative access to an Emby Server system, depending on certain user account settings. By spoofing certain headers which are intended for interoperation with reverse proxy servers, it may be possible to affect the local/non-local network determination to allow logging in without password or to view a list of user accounts which may have no password configured. Impacted are all Emby Server system which are publicly accessible and where the administrator hasn't tightened the account login configuration for administrative users. This issue has been patched in Emby Server Beta version 4.8.31 and Emby Server version 4.7.12.

Weakness: CWE-444 (Inconsistent Interpretation of HTTP Requests)

## Which versions are affected by CVE-2023-33193?

It affects 1 product.


Products: Emby Emby.releases.

## How do I fix CVE-2023-33193?

No fix has been published for CVE-2023-33193 yet. Limit exposure of the affected software until one is available.

## Is CVE-2023-33193 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2023-33193 exists.

Public exploit code:

- Emby Server - Authentication Bypass (nuclei): http/cves/2023/CVE-2023-33193.yaml

## Other vulnerabilities in EmbySupport security

- [CVE-2021-32833](https://insights.sbomify.com/CVE-2021-32833/): Unauthenticated file read in Emby Server (high 8.6)
- [CVE-2023-4167](https://insights.sbomify.com/CVE-2023-4167/): Media Browser Emby Server cross site scripting (low 3.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2023-33193 and fix it if it is affected.

What it is: CVE-2023-33193 is a critical authentication bypass vulnerability in EmbySupport security, published on 30 May 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-2023-33193 exists.

Affected product: EmbySupport security. 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-2023-33193/ (Markdown: https://insights.sbomify.com/CVE-2023-33193/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2023-33193
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-33193
- OSV: https://osv.dev/vulnerability/CVE-2023-33193

---
From sbomify Insights: https://insights.sbomify.com/CVE-2023-33193/
Summaries are generated and may contain mistakes; the official description above is the record.