Authentication bypass via spoofed proxy address
Published Jun 28, 2023 · Updated Feb 13, 2025
Authentication bypass in Emby Server before 4.7.12.0 allows remote attackers to gain passwordless access via spoofed proxy headers. The local-network determination trusts attacker-supplied X-Forwarded-For or X-Real-IP values, so a local address activates password-optional sign-in behavior. Exploitation requires a network-accessible server and an account configured without a password or to omit passwords on the local network; an exposed administrative account grants administrative access.
Summary
What happened
Authentication bypass in Emby Server before 4.7.12.0 allows remote attackers to gain passwordless access via spoofed proxy headers. The local-network determination trusts attacker-supplied X-Forwarded-For or X-Real-IP values, so a local address activates password-optional sign-in behavior. Exploitation requires a network-accessible server and an account configured without a password or to omit passwords on the local network; an exposed administrative account grants administrative access.
The record
- CVE
- CVE-2021-25827
- Published
- Jun 28, 2023
- Updated
- Feb 13, 2025
- Vendor
- Unknown vendor
- Product
- Unknown product
- Classifications
- CWE-290, T1190
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Jun 28, 2023CVE publishedPublication date reported by the CVE source.
- Feb 13, 2025Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
Compare your product and version with the public record. A matching version still requires validation against your environment.
Is a vulnerable build present?
What conditions does exploitation require?
What is affected?
Affected products and versions are unavailable in this record.
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
- X-Forwarded-For local-address reproductionproof of concept · demonstrated
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
See the directory against your own environment.
Your stack
Check the software in your environment
Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.
Book a demo