Caddy is an extensible server platform that uses TLS by default. In version 2.11.3 and earlier, three configuration-dependent weaknesses affect the handler and placeholder layer. In modules/caddyhttp/rewrite/rewrite.go, Rewrite.Rewrite() can pass attacker-controlled replacement bytes through buildQueryString for a second placeholder expansion when a rewrite URI ends with a literal question mark, allowing injected environment or request-variable placeholders to disclose data and, when the file provider is registered, allowing injected file placeholders to disclose readable files.
The issue is fixed in version 2.11.4.
Attack Parameters
Attack Vector
Network
Can be exploited remotely
Attack Complexity
Low
Easy to exploit
Privileges Required
None
No privileges needed
User Interaction
None
No user interaction needed
Impact Assessment
Confidentiality
Low
Partial data leak
Integrity
None
No data modification
Availability
Low
Partial disruption
CVSS Vector v3.1
Weakness Type (CWE)
References 4
https://github.com/caddyserver/caddy/commit/176b043b0104cee3f894023cd5a598ac29e…
security-advisories@github.com
https://github.com/caddyserver/caddy/pull/7761
security-advisories@github.com
https://github.com/caddyserver/caddy/releases/tag/v2.11.4
security-advisories@github.com
https://github.com/caddyserver/caddy/security/advisories/GHSA-j8px-rmrx-76h9
security-advisories@github.com