Skip to main content

Emby CVE-2023-33193

CRITICAL
HTTP Request/Response Smuggling (CWE-444)
2023-05-30 security-advisories@github.com
9.1
CVSS 3.1 · NVD
View

Vulnerability Assessment

Weakness
CWE
OWASP Top 10:2025
A06:2025 - Insecure Design
ASVS 5.0
V4 - API and Web Service HTTP request consistency
Impact

CVSS score of 9.1 (CRITICAL). Attack characteristics: network attack vector, low complexity, no privileges required, no user interaction not required.

Exploit ScenarioDerived

A remote attacker could manipulate HTTP request interpretation between frontend and backend servers by sending crafted requests to the affected application. No authentication is required to exploit this vulnerability.

Act Now Prioritize within 24-48h. Why: CRITICAL severity + public POC available.
No patch listed yet 1.7% exploitation probability (EPSS)

Get an e-mail when this CVE is exploited, patched or re-scored. Free account.

Alert me

AnalysisAI

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. Rated critical severity (CVSS 9.1), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.

RemediationAI

No vendor patch is available at time of analysis. Monitor vendor advisories for updates. Enforce strict HTTP parsing, normalize requests at proxy layer, use HTTP/2 end-to-end, reject ambiguous headers.

Affects your stack

Find out whether the stacks and servers you run are on an affected version.

Checking this CVE against your own stacks and servers is part of the Basic plan and up.

Technical ContextAI · show details

This vulnerability is classified as HTTP Request/Response Smuggling (CWE-444), which allows attackers to manipulate HTTP request interpretation between frontend and backend servers. 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. Affected products include: Emby Emby.Releases. Version information: version 4.8.31.

Know when Emby gets its next vulnerability

  • Watch products and get an email when something new is published
  • Check this CVE against your own stack and servers
  • Exploit and PoC references, threat intelligence from 22 sources

No credit card · 7-day full trial

Severity by source

NVD PRIMARY 9.1 CRITICAL
AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

Primary rating from NVD · only source for this CVE.

CVSS VectorNVD

Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
None

DescriptionNVD

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.

Threat Intelligence Overview

EPSS Score
1.7%
Top 25% exploitable
Exploit
POC
Public exploit code exists
Data Quality
3 sources
Confidence: Low

How this decision was reached

The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.

SignalValue
Severity CRITICAL
CISA KEV No
Public POC Yes
EPSS 1.7%
Patch available No
Active threat No
Deciding rule
CRITICAL severity + public POC available
What every action level means
Emergency Immediate action required. Criteria: CRITICAL + in CISA KEV (actively exploited) without patch, OR CRITICAL + EPSS > 30% without patch, OR CRITICAL + active threat signals without patch.
Act Now Prioritize within 24-48h. Criteria: in KEV with patch available, OR CRITICAL + public POC, OR HIGH + EPSS > 10%, OR CRITICAL + active threat, OR any CRITICAL severity.
This Week Schedule remediation this week. Criteria: HIGH severity (CVSS 7.0-8.9). Patch within normal change window.
This Month Plan within 30 days. Criteria: MEDIUM severity (CVSS 4.0-6.9), lower exploitation probability. Include in regular patch cycle.
Monitor Track and reassess. Criteria: LOW severity (CVSS 0.1-3.9), minimal exploitation risk. No immediate action needed.

SSVC AssessmentENISA

SSVC Decision· derived
Scheduled
Exploitation· derived
Poc
System Exposure· derived
Open
Automatable· derived
Yes
Human Impact· derived
Medium

Priority Score

68
Low Medium High Critical
KEV: 0
EPSS: +2
CVSS: +46
PoC: +20
Weaponized: 0
Threat intel: 0
Gov advisory: 0

Attack Technique

HTTP request smuggling exploits inconsistencies in how front-end and back-end servers parse HTTP message boundaries.

Information disclosure occurs when an application unintentionally exposes sensitive data that aids attackers in reconnaissance or directly compromises security.

Affected Products (CPE)NVD

cpe:2.3:a:emby:emby.releases:*:*:*:*:*:*:*:*
cpe:2.3:a:emby:emby.releases:*:*:*:*:*:*:*:*

This site uses cookies essential for authentication and security. No tracking or analytics cookies are used. Privacy Policy