Caddy is an extensible server platform that uses TLS by default. Prior to version 2.11.1, the local caddy admin API (default listen `127.0.0.1:2019`) exposes a state-changing `POST /load` endpoint that replaces the entire running configuration. When origin enforcement is not enabled (`enforce_origin` not configured), the admin endpoint accepts cross-origin requests (e.g., from attacker-controlled web content in a victim browser) and applies an attacker-supplied JSON config.
This can change the admin listener settings and alter HTTP server behavior without user intent. Version 2.11.1 contains a fix for the issue.
Attack Parameters
Attack Vector
Network
Can be exploited remotely
Attack Complexity
Low
Easy to exploit
Attack Requirements
Present
Additional conditions required
Privileges Required
None
No privileges needed
User Interaction
None
No user interaction needed
Impact Assessment
Confidentiality
None
No data leak
Integrity
High
Complete data modification
Availability
None
No disruption
CVSS Vector v4.0
Weakness Type (CWE)
Vulnerable Products 1
| Configuration | From (including) | Up to (excluding) |
|---|---|---|
|
Caddyserver Caddy
cpe:2.3:a:caddyserver:caddy:*:*:*:*:*:*:*:*
|
— |
2.11.1
|
References 4
https://github.com/caddyserver/caddy/releases/tag/v2.11.1
security-advisories@github.com
https://github.com/caddyserver/caddy/security/advisories/GHSA-879p-475x-rqh2
security-advisories@github.com
https://github.com/user-attachments/files/25079818/poc.zip
security-advisories@github.com
https://github.com/user-attachments/files/25079820/PR_DESCRIPTION.md
security-advisories@github.com