Index: httpd-2.4.33/include/http_protocol.h
===================================================================
--- httpd-2.4.33.orig/include/http_protocol.h	2017-05-30 14:27:41.000000000 +0200
+++ httpd-2.4.33/include/http_protocol.h	2022-01-05 10:34:33.100267847 +0100
@@ -75,6 +75,13 @@ AP_DECLARE(void) ap_get_mime_headers(req
 AP_DECLARE(void) ap_get_mime_headers_core(request_rec *r,
                                           apr_bucket_brigade *bb);
 
+/**
+ * Run post_read_request hook and validate.
+ * @param r The current request
+ * @return OK or HTTP_...
+ */
+AP_DECLARE(int) ap_post_read_request(request_rec *r);
+
 /* Finish up stuff after a request */
 
 /**
Index: httpd-2.4.33/modules/http/http_request.c
===================================================================
--- httpd-2.4.33.orig/modules/http/http_request.c	2018-03-16 00:19:12.000000000 +0100
+++ httpd-2.4.33/modules/http/http_request.c	2022-01-05 10:34:33.100267847 +0100
@@ -662,7 +662,7 @@ static request_rec *internal_internal_re
      * to do their thing on internal redirects as well.  Perhaps this is a
      * misnamed function.
      */
-    if ((access_status = ap_run_post_read_request(new))) {
+    if ((access_status = ap_post_read_request(new))) {
         ap_die(access_status, new);
         return NULL;
     }
Index: httpd-2.4.33/modules/http2/h2_request.c
===================================================================
--- httpd-2.4.33.orig/modules/http2/h2_request.c	2022-01-05 10:34:33.100267847 +0100
+++ httpd-2.4.33/modules/http2/h2_request.c	2022-01-05 10:37:34.469281690 +0100
@@ -345,7 +345,7 @@ request_rec *h2_request_create_rec(const
                                NULL, r, r->connection);
     
     if (access_status != HTTP_OK
-        || (access_status = ap_run_post_read_request(r))) {
+        || (access_status = ap_post_read_request(r))) {
         /* Request check post hooks failed. An example of this would be a
          * request for a vhost where h2 is disabled --> 421.
          */
Index: httpd-2.4.33/modules/proxy/mod_proxy.c
===================================================================
--- httpd-2.4.33.orig/modules/proxy/mod_proxy.c	2022-01-05 10:34:33.088267779 +0100
+++ httpd-2.4.33/modules/proxy/mod_proxy.c	2022-01-05 10:40:23.114224450 +0100
@@ -573,13 +573,13 @@ static int proxy_detect(request_rec *r)
 
     /* Ick... msvc (perhaps others) promotes ternary short results to int */
 
-    if (conf->req && r->parsed_uri.scheme) {
+    if (conf->req && r->parsed_uri.scheme && r->parsed_uri.hostname) {
         /* but it might be something vhosted */
-        if (!(r->parsed_uri.hostname
-              && !strcasecmp(r->parsed_uri.scheme, ap_http_scheme(r))
-              && ap_matches_request_vhost(r, r->parsed_uri.hostname,
-                                          (apr_port_t)(r->parsed_uri.port_str ? r->parsed_uri.port
-                                                       : ap_default_port(r))))) {
+        if (ap_cstr_casecmp(r->parsed_uri.scheme, ap_http_scheme(r)) != 0
+            || !ap_matches_request_vhost(r, r->parsed_uri.hostname,
+                                         (apr_port_t)(r->parsed_uri.port_str
+                                                      ? r->parsed_uri.port
+                                                      : ap_default_port(r)))) {
             r->proxyreq = PROXYREQ_PROXY;
             r->uri = r->unparsed_uri;
             r->filename = apr_pstrcat(r->pool, "proxy:", r->uri, NULL);
@@ -1719,6 +1719,7 @@ static const char *
     struct proxy_alias *new;
     char *f = cmd->path;
     char *r = NULL;
+    const char *real;
     char *word;
     apr_table_t *params = apr_table_make(cmd->pool, 5);
     const apr_array_header_t *arr;
@@ -1785,6 +1786,10 @@ static const char *
     if (r == NULL) {
         return "ProxyPass|ProxyPassMatch needs a path when not defined in a location";
     }
+    if (!(real = ap_proxy_de_socketfy(cmd->temp_pool, r))) {
+        return "ProxyPass|ProxyPassMatch uses an invalid \"unix:\" URL";
+    }
+
 
     /* if per directory, save away the single alias */
     if (cmd->path) {
@@ -1801,7 +1806,7 @@ static const char *
     }
 
     new->fake = apr_pstrdup(cmd->pool, f);
-    new->real = apr_pstrdup(cmd->pool, ap_proxy_de_socketfy(cmd->pool, r));
+    new->real = apr_pstrdup(cmd->pool, real);
     new->flags = flags;
     if (worker_type & AP_PROXY_WORKER_IS_MATCH) {
         new->regex = ap_pregcomp(cmd->pool, f, AP_REG_EXTENDED);
@@ -2281,6 +2286,7 @@ static const char *add_member(cmd_parms
     proxy_worker *worker;
     char *path = cmd->path;
     char *name = NULL;
+    const char *real;
     char *word;
     apr_table_t *params = apr_table_make(cmd->pool, 5);
     const apr_array_header_t *arr;
@@ -2321,6 +2327,9 @@ static const char *add_member(cmd_parms
         return "BalancerMember must define balancer name when outside <Proxy > section";
     if (!name)
         return "BalancerMember must define remote proxy server";
+    if (!(real = ap_proxy_de_socketfy(cmd->temp_pool, name))) {
+        return "BalancerMember uses an invalid \"unix:\" URL";
+    }
 
     ap_str_tolower(path);   /* lowercase scheme://hostname */
 
@@ -2333,8 +2342,7 @@ static const char *add_member(cmd_parms
     }
 
     /* Try to find existing worker */
-    worker = ap_proxy_get_worker(cmd->temp_pool, balancer, conf,
-                                 ap_proxy_de_socketfy(cmd->temp_pool, name));
+    worker = ap_proxy_get_worker(cmd->temp_pool, balancer, conf, real);
     if (!worker) {
         ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, cmd->server, APLOGNO(01147)
                      "Defining worker '%s' for balancer '%s'",
@@ -2431,9 +2439,14 @@ static const char *
         }
     }
     else {
+        const char *real;
+
+        if (!(real = ap_proxy_de_socketfy(cmd->temp_pool, name))) {
+            return "ProxySet uses an invalid \"unix:\" URL";
+        }
+
         worker = ap_proxy_get_worker_ex(cmd->temp_pool, NULL, conf,
-                                        ap_proxy_de_socketfy(cmd->temp_pool, name),
-                                        worker_type);
+                                        real, worker_type);
         if (!worker) {
             if (in_proxy_section) {
                 err = ap_proxy_define_worker_ex(cmd->pool, &worker, NULL,
@@ -2578,9 +2591,14 @@ static const char *proxysection(cmd_parm
             }
         }
         else {
+            const char *real;
+
+            if (!(real = ap_proxy_de_socketfy(cmd->temp_pool, conf->p))) {
+                return "<Proxy/ProxyMatch > uses an invalid \"unix:\" URL";
+            }
+
             worker = ap_proxy_get_worker_ex(cmd->temp_pool, NULL, sconf,
-                                            ap_proxy_de_socketfy(cmd->temp_pool, conf->p),
-                                            worker_type);
+                                            real, worker_type);
             if (!worker) {
                 err = ap_proxy_define_worker_ex(cmd->pool, &worker, NULL, sconf,
                                                 conf->p, worker_type);
Index: httpd-2.4.33/modules/proxy/proxy_util.c
===================================================================
--- httpd-2.4.33.orig/modules/proxy/proxy_util.c	2022-01-05 10:34:33.088267779 +0100
+++ httpd-2.4.33/modules/proxy/proxy_util.c	2022-01-05 10:34:33.100267847 +0100
@@ -1525,6 +1525,9 @@ PROXY_DECLARE(proxy_worker *) ap_proxy_g
     }
 
     url = ap_proxy_de_socketfy(p, url);
+    if (!url) {
+        return NULL;
+    }
 
     c = ap_strchr_c(url, ':');
     if (c == NULL || c[1] != '/' || c[2] != '/' || c[3] == '\0') {
Index: httpd-2.4.33/server/protocol.c
===================================================================
--- httpd-2.4.33.orig/server/protocol.c	2022-01-05 10:34:32.772266013 +0100
+++ httpd-2.4.33/server/protocol.c	2022-01-05 10:46:31.256289079 +0100
@@ -1401,7 +1401,7 @@ request_rec *ap_read_request(conn_rec *c
                                NULL, r, r->connection);
 
     if (access_status != HTTP_OK
-        || (access_status = ap_run_post_read_request(r))) {
+        || (access_status = ap_post_read_request(r))) {
         ap_die(access_status, r);
         ap_update_child_status(conn->sbh, SERVER_BUSY_LOG, r);
         ap_run_log_transaction(r);
@@ -1448,6 +1448,27 @@ request_rec *ap_read_request(conn_rec *c
     return r;
 }
 
+AP_DECLARE(int) ap_post_read_request(request_rec *r)
+{
+    int status;
+
+    if ((status = ap_run_post_read_request(r))) {
+        return status;
+    }
+
+    /* Enforce http(s) only scheme for non-forward-proxy requests */
+    if (!r->proxyreq
+            && r->parsed_uri.scheme
+            && (ap_cstr_casecmpn(r->parsed_uri.scheme, "http", 4) != 0
+                || (r->parsed_uri.scheme[4] != '\0'
+                    && (apr_tolower(r->parsed_uri.scheme[4]) != 's'
+                        || r->parsed_uri.scheme[5] != '\0')))) {
+        return HTTP_BAD_REQUEST;
+    }
+
+    return OK;
+}
+
 /* if a request with a body creates a subrequest, remove original request's
  * input headers which pertain to the body which has already been read.
  * out-of-line helper function for ap_set_sub_req_protocol.
