From c8f2834b514f8bfb405c11be53d60a6cfc5228ca Mon Sep 17 00:00:00 2001 From: Francis Lavoie Date: Mon, 7 Mar 2022 12:06:33 -0500 Subject: fastcgi: Protect against requests with null bytes in the path (#4614) --- modules/caddyhttp/reverseproxy/fastcgi/fastcgi.go | 7 +++++++ 1 file changed, 7 insertions(+) (limited to 'modules/caddyhttp/reverseproxy/fastcgi') diff --git a/modules/caddyhttp/reverseproxy/fastcgi/fastcgi.go b/modules/caddyhttp/reverseproxy/fastcgi/fastcgi.go index 18d7e75..2848133 100644 --- a/modules/caddyhttp/reverseproxy/fastcgi/fastcgi.go +++ b/modules/caddyhttp/reverseproxy/fastcgi/fastcgi.go @@ -110,6 +110,13 @@ func (t *Transport) Provision(ctx caddy.Context) error { // RoundTrip implements http.RoundTripper. func (t Transport) RoundTrip(r *http.Request) (*http.Response, error) { + // Disallow null bytes in the request path, because + // PHP upstreams may do bad things, like execute a + // non-PHP file as PHP code. See #4574 + if strings.Contains(r.URL.Path, "\x00") { + return nil, caddyhttp.Error(http.StatusBadRequest, fmt.Errorf("invalid request path")) + } + env, err := t.buildEnv(r) if err != nil { return nil, fmt.Errorf("building environment: %v", err) -- cgit v1.2.3