merge from trunk and 2.2.x, using existing published patch for 2.0.63:

  *) SECURITY: CVE-2008-2364 (cve.mitre.org)
     mod_proxy_http: Better handling of excessive interim responses
     from origin server to prevent potential denial of service and high
     memory usage. Reported by Ryujiro Shibuya. [Ruediger Pluem,
     Joe Orton, Jim Jagielski]

Reviewed by: trawick, wrowe, rpluem

git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/2.0.x@921908 13f79535-47bb-0310-9956-ffa450edef68

diff --git a/CHANGES b/CHANGES
index 0dfbae62d37b224bd821b5dcb9c71d7c9c220a5b..25ba0d81d6cfcc903c5eaf4cc5720301bbdb740a 100644 (file)
--- a/CHANGES
+++ b/CHANGES
@@ -1,6 +1,12 @@
                                                          -*- coding: utf-8 -*-
 Changes with Apache 2.0.64
 
+  *) SECURITY: CVE-2008-2364 (cve.mitre.org)
+     mod_proxy_http: Better handling of excessive interim responses
+     from origin server to prevent potential denial of service and high
+     memory usage. Reported by Ryujiro Shibuya. [Ruediger Pluem,
+     Joe Orton, Jim Jagielski]
+
   *) SECURITY: CVE-2010-0425 (cve.mitre.org)
      mod_isapi: Do not unload an isapi .dll module until the request
      processing is completed, avoiding orphaned callback pointers.

diff --git a/STATUS b/STATUS
index 9d5e7b630dc181756097d41f9568015bde815be8..fc12932d1b4ab274697257302053bd498b3dbaf7 100644 (file)
--- a/STATUS
+++ b/STATUS
@@ -114,13 +114,6 @@ CURRENT RELEASE NOTES:
 
 RELEASE SHOWSTOPPERS:
 
-  * Commit /dist/httpd/patches/apply_to_2.0.63/CVE-2008-2364-patch-2.0.txt:
-    SECURITY: CVE-2008-2364 (cve.mitre.org)
-    mod_proxy_http: Better handling of excessive interim responses
-    from origin server to prevent potential denial of service and high
-    memory usage.
-    +1: trawick, wrowe, rpluem
-
   * Commit http://people.apache.org/~wrowe/CVE-2010-0434.patch
     SECURITY: CVE-2010-0434 (cve.mitre.org)
     note; simpler because we had not yet cleaned up input headers for subreq

diff --git a/modules/proxy/proxy_http.c b/modules/proxy/proxy_http.c
index 6cc187dbcd3fe1953e9c6fc1b09c18adeded262e..ca5f038b5ff2346f285bb73dc311a790914b86a1 100644 (file)
--- a/modules/proxy/proxy_http.c
+++ b/modules/proxy/proxy_http.c
@@ -1290,6 +1290,16 @@ static int addit_dammit(void *v, const char *key, const char *val)
     return 1;
 }
 
+/*
+ * Limit the number of interim respones we sent back to the client. Otherwise
+ * we suffer from a memory build up. Besides there is NO sense in sending back
+ * an unlimited number of interim responses to the client. Thus if we cross
+ * this limit send back a 502 (Bad Gateway).
+ */
+#ifndef AP_MAX_INTERIM_RESPONSES
+#define AP_MAX_INTERIM_RESPONSES 10
+#endif
+
 static
 apr_status_t ap_proxy_http_process_response(apr_pool_t * p, request_rec *r,
                                             proxy_http_conn_t *p_conn,
@@ -1322,7 +1332,7 @@ apr_status_t ap_proxy_http_process_response(apr_pool_t * p, request_rec *r,
      */
     rp->proxyreq = PROXYREQ_RESPONSE;
 
-    while (received_continue) {
+    while (received_continue && (received_continue <= AP_MAX_INTERIM_RESPONSES)) {
         apr_brigade_cleanup(bb);
 
         len = ap_getline(buffer, sizeof(buffer), rp, 0);
@@ -1440,7 +1450,9 @@ apr_status_t ap_proxy_http_process_response(apr_pool_t * p, request_rec *r,
             if ((buf = apr_table_get(r->headers_out, "Content-Type"))) {
                 ap_set_content_type(r, apr_pstrdup(p, buf));
             }            
-            ap_proxy_pre_http_request(origin,rp);
+            if (!ap_is_HTTP_INFO(r->status)) {
+                ap_proxy_pre_http_request(origin, rp);
+            }
 
             /* handle Via header in response */
             if (conf->viaopt != via_off && conf->viaopt != via_block) {
@@ -1486,6 +1498,7 @@ apr_status_t ap_proxy_http_process_response(apr_pool_t * p, request_rec *r,
         if ( r->status != HTTP_CONTINUE ) {
             received_continue = 0;
         } else {
+            received_continue++;
             ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, NULL,
                          "proxy: HTTP: received 100 CONTINUE");
         }
@@ -1622,6 +1635,14 @@ apr_status_t ap_proxy_http_process_response(apr_pool_t * p, request_rec *r,
         }
     }
 
+    /* See define of AP_MAX_INTERIM_RESPONSES for why */
+    if (received_continue > AP_MAX_INTERIM_RESPONSES) {
+        return ap_proxyerror(r, HTTP_BAD_GATEWAY,
+                             apr_psprintf(p, 
+                             "Too many (%d) interim responses from origin server",
+                             received_continue));
+    }
+
     if ( conf->error_override ) {
         /* the code above this checks for 'OK' which is what the hook expects */
         if ( r->status == HTTP_OK )