Authentication bypass via trusted X-Forwarded-For header
Published Feb 17, 2024 · Updated Apr 24, 2025
Authentication bypass in Greenpau Caddy Security through 1.1.23 allows remote attackers to gain unauthorized access via a forged X-Forwarded-For header. The /whoami identity endpoint accepts the client-supplied header as the user's IP address without validating it against the connection source. Exploitation requires a deployment that exposes the endpoint and treats that reported IP address as an authorization or trust signal.
Summary
What happened
Authentication bypass in Greenpau Caddy Security through 1.1.23 allows remote attackers to gain unauthorized access via a forged X-Forwarded-For header. The /whoami identity endpoint accepts the client-supplied header as the user's IP address without validating it against the connection source. Exploitation requires a deployment that exposes the endpoint and treats that reported IP address as an authorization or trust signal.
The record
- CVE
- CVE-2024-21494
- Published
- Feb 17, 2024
- Updated
- Apr 24, 2025
- Vendor
- Greenpau
- Product
- Caddy Security
- Classifications
- CWE-290, CWE-79, T1190
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Feb 17, 2024CVE publishedPublication date reported by the CVE source.
- Apr 24, 2025Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=0 <=*
- Affected versionversion=0 <*
What conditions does exploitation require?
What is affected?
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 IP spoofing demonstrationproof of concept · demonstrated
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
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Your stack
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