* Implement HTTPoxy mitigation in FastCGI
Added HTTPoxy mitigation to prevent trusting client-supplied Proxy header for HTTP_PROXY environment variable.
* Implement test for HTTPoxy vulnerability protection
Add test to ensure HTTPoxy vulnerability is mitigated by dropping client-supplied Proxy headers.
* gofmt: format code
* revert unrelated gofmt change to replacer_test.go
Caddy's underscore header filter (GHSA-f59h-q822-g45g) only checked
for `_`. PHP folds `.` to `_` when registering $_SERVER keys the same
way CGI/FastCGI folds `-` to `_`, so a dotted alias (e.g. Remote.User)
survived the filter and collided with the legitimate hyphenated
header once it reached a PHP/FastCGI backend, bypassing forward_auth
copy_headers the same way the underscore alias did.
Extends the filter to drop `.` symmetrically, adds an
`expected_dot_headers` allowlist mirroring `expected_underscore_headers`,
and handles header names containing both separators (only an exact
allowlist entry is honored there, since a prefix glob's free-form
suffix can't be vetted for an embedded second separator).
Root cause identified by @iliaal in the FrankenPHP advisory
GHSA-49wc-4hcv-v58q.
* feat(fastcgi): populate SERVER_ADDR by default
Populate the SERVER_ADDR FastCGI environment variable using the local socket address of the incoming connection from the request context. This improves out-of-the-box compatibility for PHP applications that rely on $_SERVER['SERVER_ADDR'] (such as legacy frameworks and custom telemetry packages) when migrating from Nginx or Apache.
Co-developed-by: Gemini AI <renich+gemini@woralelandia.com>
Signed-off-by: Rénich Bon Ćirić <renich@woralelandia.com>
* fix(fastcgi): validate SERVER_ADDR IP format and add test coverage
Validate that SERVER_ADDR is only populated when the local address parses as a valid IP address, preventing Unix socket paths from being assigned if SplitHostPort fails. Add test cases covering IPv4, IPv6, missing context, Unix sockets, and explicit overrides.
Co-developed-by: Gemini AI <renich+gemini@woralelandia.com>
Signed-off-by: Rénich Bon Ćirić <renich@woralelandia.com>
* feat: drop headers with underscore in their names
* feat: Caddyfile binding and tests for underscore-in-header drop
Add the `allow_underscore_in_headers` global server option, refine the
doc comment, and cover the filter end-to-end: server-level unit tests
(drop, opt-out, debug log, RFC-7230 space rejection), a fastcgi unit
test for the trimmed header name replacer, and forward_auth integration
tests for both the default-drop and opt-out paths.
* remove allow_underscore_in_headers option for now
Both fallbacks in splitPos relied on golang.org/x/text/search with
search.IgnoreCase, which performs Unicode equivalence matching far beyond
ASCII case folding. Combined with the validated-ASCII guarantee on every
SplitPath entry, that fallback turned non-PHP filenames into PHP scripts:
- when the inner loop hit a non-ASCII byte and the IndexString fallback
returned -1, the loop broke without resetting match=false, so a stale
match=true caused a non-existent .php to be reported (PoC:
"/name.<U+00A1>.txt").
- search.IgnoreCase folded fullwidth, mathematical and circled letters
onto ASCII, so "/shell.<math sans-serif php>",
"/shell.<fullwidth p>hp", "/shell.<circled php>" were all detected as
".php" files.
Replace the fallback with strict byte-level ASCII case-insensitive
matching: any byte >= utf8.RuneSelf in the path can never be part of a
match, since SplitPath entries are validated ASCII-only and lower-cased
in Provision(). This keeps the hot path branch-light and removes the
x/text/search dependency from the main module.
Reported against FrankenPHP as GHSA-3g8v-8r37-cgjm and
GHSA-v4h7-cj44-8fc8. The vulnerable function in this module was adapted
from the same FrankenPHP code.
* use gofmput to format code
* use gci to format imports
* reconfigure gci
* linter autofixes
* rearrange imports a little
* export GOOS=windows golangci-lint run ./... --fix
Ideally I'd just remove the parameter to caddy.Context.Logger(), but
this would break most Caddy plugins.
Instead, I'm making it variadic and marking it as partially deprecated.
In the future, I might completely remove the parameter once most
plugins have updated.
* break up code and use lazy reading and pool bufio.Writer
* close underlying connection when operation failed
* allocate bufWriter and streamWriter only once
* refactor record writing
* rebase from master
* handle err
* Fix type assertion
Also reduce some duplication
* Refactor client and clientCloser for logging
Should reduce allocations
* Minor cosmetic adjustments; apply Apache license
* Appease the linter
Co-authored-by: Matthew Holt <mholt@users.noreply.github.com>
* fastcgi: Fix a TODO, prevent zap using reflection for logging env
* Update modules/caddyhttp/reverseproxy/fastcgi/fastcgi.go
Co-authored-by: Mohammed Al Sahaf <msaa1990@gmail.com>
Co-authored-by: Mohammed Al Sahaf <msaa1990@gmail.com>
* reverseproxy: Adjust defaults, document defaults
Related to some of the issues in https://github.com/caddyserver/caddy/issues/4245, a complaint about the proxy transport defaults not being properly documented in https://caddy.community/t/default-values-for-directives/14254/6.
- Dug into the stdlib to find the actual defaults for some of the timeouts and buffer limits, documenting them in godoc so the JSON docs get them next release.
- Moved the keep-alive and dial-timeout defaults from `reverseproxy.go` to `httptransport.go`. It doesn't make sense to set defaults in the proxy, because then any time the transport is configured with non-defaults, the keep-alive and dial-timeout defaults are lost!
- Sped up the dial timeout from 10s to 3s, in practice it rarely makes sense to wait a whole 10s for dialing. A shorter timeout helps a lot with the load balancer retries, so using something lower helps with user experience.
* reverseproxy: Make keepalive interval configurable via Caddyfile
* fastcgi: DialTimeout default for fastcgi transport too
* reverseproxy: Add `handle_response` blocks to `reverse_proxy` (#3710)
* reverseproxy: complete handle_response test
* reverseproxy: Change handle_response matchers to use named matchers
reverseproxy: Add support for changing status code
* fastcgi: Remove obsolete TODO
We already have d.Err("transport already specified") in the reverse_proxy parsing code which covers this case
* reverseproxy: Fix support for "4xx" type status codes
* Apply suggestions from code review
Co-authored-by: Matt Holt <mholt@users.noreply.github.com>
* caddyhttp: Reorganize response matchers
* reverseproxy: Reintroduce caddyfile.Unmarshaler
* reverseproxy: Add comment mentioning Finalize should be called
Co-authored-by: Maxime Soulé <btik-git@scoubidou.com>
Co-authored-by: Matt Holt <mholt@users.noreply.github.com>
* fastcgi: Set PATH_INFO to file matcher remainder as fallback
* fastcgi: Avoid changing scriptName when not necessary
* Stylistic tweaks
Co-authored-by: Matthew Holt <mholt@users.noreply.github.com>
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