Emby.releasesApplication · Emby

CVE-2023-33193

CRITICAL · 9.1 CVSS v3.1 Published 2023-05-30
Fix available
A fix is available. Upgrade to 4.7.0.12 / 4.8.31 or later.
See remediation →
100/100
Remediation priority · Urgent
Remotely reachable No privileges Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
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.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

Authentication bypass vulnerability in Emby Server allowing admin access by spoofing reverse proxy headers (e.g., X-Forwarded-For, X-Real-IP) to manipulate the server's local/non-local network trust determination. This enables unauthenticated login without password or enumeration of user accounts with potentially no password configured.

MitigationUpdate Emby Server to version 4.7.12 or 4.8.31 (beta). Additionally, avoid public exposure of the server and ensure administrative accounts have strong passwords configured rather than relying on network-based trust.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
Emby.releasesApplication
Affected:< 4.7.0.12>= 4.8.0.0, < 4.8.31

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
None

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

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Determine your Emby Server version
    Log into the Emby web dashboard, navigate to the Dashboard (cog icon), then click About. Alternatively, access the server info via the API endpoint /emby/System/Info or check the emby-server package version on the host system.
    Affected if The installed version is below 4.7.12 (e.g., any version < 4.7.0.12) or is between 4.8.0.0 and 4.8.30 inclusive.
  2. Identify if a reverse proxy is in front of Emby
    Inspect your network architecture: check for nginx, Apache, HAProxy, Caddy, or cloudflare configured to forward requests to Emby. Look for proxy_pass directives in nginx/apache configs or reverse proxy settings in your infrastructure.
    Affected if A reverse proxy or load balancer sits in front of Emby Server and forwards client requests to it.
  3. Check if Emby is configured to trust proxy headers
    In the Emby Dashboard, go to Networking > Advanced. Look for settings like "Trust reverse proxy IP addresses", "Allow IP addresses to be forwarded", or any configuration that allows remote clients to appear as local. Alternatively, inspect the system/advanced endpoint via the Emby API for trust-related flags.
    Affected if The server has enabled any setting that instructs Emby to trust X-Forwarded-For, X-Real-IP, or similar headers from incoming requests without additional validation.
  4. Verify server is accessible from untrusted networks
    Determine if the Emby web interface (ports 8096 or 8920) is open to the public internet or any network beyond your administrative LAN. Check firewall rules, router port forwarding, or cloud security group configurations that allow external access.
    Affected if Emby Server is directly exposed to the internet or to networks outside your trusted internal network without a properly configured reverse proxy performing header validation.
  5. Confirm admin accounts have passwords set
    In the Emby Dashboard, navigate to Users > select each user (especially administrators). Verify that a password is configured for each admin-level account. Check via the API endpoint /emby/Users for user accounts with empty or null Password values.
    Affected if Any administrative account exists with no password configured, which would allow the bypass to enumerate and potentially access that account without authentication.

You are affected if your Emby Server version is below 4.7.12 or between 4.8.0.0 and 4.8.30, AND the server trusts reverse proxy headers (X-Forwarded-For/X-Real-IP) from clients, AND is accessible from untrusted networks where an attacker could spoof these headers.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 4.7.0.12 / 4.8.31 or later
Fixed in 4.7.0.124.8.31
Interim mitigation

Update Emby Server to version 4.7.12 or 4.8.31 (beta). Additionally, avoid public exposure of the server and ensure administrative accounts have strong passwords configured rather than relying on network-based trust.

Recommended fix High confidence

Emby Server 4.7.12 (for 4.7.x line) or 4.8.31+ (for 4.8.x line)

  1. 1. Identify your current Emby Server version via the admin dashboard or by checking the system information
  2. 2. If running a version < 4.7.0.12, upgrade to Emby Server version 4.7.12 or later
  3. 3. If running version >= 4.8.0.0 and < 4.8.31, upgrade to Emby Server version 4.8.31 or later (the beta version mentioned in the advisory)
  4. 4. After upgrading, verify the new version is running by checking the admin dashboard
  5. 5. Review and harden administrative account login configuration to ensure strong passwords are required, as recommended in the CVE description
Caveat Check Emby release notes for your specific upgrade path for any breaking changes between versions

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Emby.releases Scoped from the published advisory
  • Consultation2.0 h
  • Implementation1.0 h
  • Testing2.0 h
  • Review / QA1.0 h
6.0 hours of engineering $1,060
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Scan for this in your stack

Free · runs locally
dbcve dependency scanner

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2023-33193 in production — separate from our analysis above.

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data