Resolves: RHEL-12728 - nginx:1.22/nginx: HTTP/2: Multiple HTTP/2 enabled web

servers are vulnerable to a DDoS attack (Rapid Reset Attack)(CVE-2023-44487)

nginx-1.22-CVE-2023-44487.patch

@@ -0,0 +1,73 @@
+From b6aa9504cdfb6391d895dcbddc87b9260ea6968c Mon Sep 17 00:00:00 2001
+From: =?UTF-8?q?Lubo=C5=A1=20Uhliarik?= <luhliari@redhat.com>
+Date: Wed, 11 Oct 2023 09:59:23 +0200
+Subject: [PATCH] CVE-2023-44487 - HTTP/2: per-iteration stream handling limit.
+
+To ensure that attempts to flood servers with many streams are detected
+early, a limit of no more than 2 * max_concurrent_streams new streams per one
+event loop iteration was introduced.  This limit is applied even if
+max_concurrent_streams is not yet reached - for example, if corresponding
+streams are handled synchronously or reset.
+
+Further, refused streams are now limited to maximum of max_concurrent_streams
+and 100, similarly to priority_limit initial value, providing some tolerance
+to clients trying to open several streams at the connection start, yet
+low tolerance to flooding attempts.
+---
+ src/http/v2/ngx_http_v2.c | 15 +++++++++++++++
+ src/http/v2/ngx_http_v2.h |  2 ++
+ 2 files changed, 17 insertions(+)
+
+diff --git a/src/http/v2/ngx_http_v2.c b/src/http/v2/ngx_http_v2.c
+index 0e45a7b..253718f 100644
+--- a/src/http/v2/ngx_http_v2.c
++++ b/src/http/v2/ngx_http_v2.c
+@@ -361,6 +361,7 @@ ngx_http_v2_read_handler(ngx_event_t *rev)
+     ngx_log_debug0(NGX_LOG_DEBUG_HTTP, c->log, 0, "http2 read handler");
+ 
+     h2c->blocked = 1;
++    h2c->new_streams = 0;
+ 
+     if (c->close) {
+         c->close = 0;
+@@ -1321,6 +1322,14 @@ ngx_http_v2_state_headers(ngx_http_v2_connection_t *h2c, u_char *pos,
+         goto rst_stream;
+     }
+ 
++    if (h2c->new_streams++ >= 2 * h2scf->concurrent_streams) {
++        ngx_log_error(NGX_LOG_INFO, h2c->connection->log, 0,
++                      "client sent too many streams at once");
++
++        status = NGX_HTTP_V2_REFUSED_STREAM;
++        goto rst_stream;
++    }
++
+     if (!h2c->settings_ack
+         && !(h2c->state.flags & NGX_HTTP_V2_END_STREAM_FLAG)
+         && h2scf->preread_size < NGX_HTTP_V2_DEFAULT_WINDOW)
+@@ -1386,6 +1395,12 @@ ngx_http_v2_state_headers(ngx_http_v2_connection_t *h2c, u_char *pos,
+ 
+ rst_stream:
+ 
++    if (h2c->refused_streams++ > ngx_max(h2scf->concurrent_streams, 100)) {
++        ngx_log_error(NGX_LOG_INFO, h2c->connection->log, 0,
++                      "client sent too many refused streams");
++        return ngx_http_v2_connection_error(h2c, NGX_HTTP_V2_NO_ERROR);
++    }
++
+     if (ngx_http_v2_send_rst_stream(h2c, h2c->state.sid, status) != NGX_OK) {
+         return ngx_http_v2_connection_error(h2c, NGX_HTTP_V2_INTERNAL_ERROR);
+     }
+diff --git a/src/http/v2/ngx_http_v2.h b/src/http/v2/ngx_http_v2.h
+index 70ee287..7593f1c 100644
+--- a/src/http/v2/ngx_http_v2.h
++++ b/src/http/v2/ngx_http_v2.h
+@@ -124,6 +124,8 @@ struct ngx_http_v2_connection_s {
+     ngx_uint_t                       processing;
+     ngx_uint_t                       frames;
+     ngx_uint_t                       idle;
++    ngx_uint_t                       new_streams;
++    ngx_uint_t                       refused_streams;
+     ngx_uint_t                       priority_limit;
+ 
+     ngx_uint_t                       pushing;

nginx.spec

@@ -30,7 +30,7 @@
 Name:              nginx
 Epoch:             1
 Version:           1.22.1
-Release:           1%{?dist}
+Release:           2%{?dist}
 
 Summary:           A high performance web server and reverse proxy server
 Group:             System Environment/Daemons
@@ -74,6 +74,9 @@ Patch4:            nginx-1.20.0-enable-tls1v3-by-default.patch
 # https://bugzilla.redhat.com/show_bug.cgi?id=1668717
 Patch5:            nginx-1.18.0-pkcs11-cert.patch
 
+# https://issues.redhat.com/browse/RHEL-12728
+Patch6:            nginx-1.22-CVE-2023-44487.patch
+
 %if 0%{?with_gperftools}
 BuildRequires:     gperftools-devel
 %endif
@@ -230,6 +233,7 @@ Requires:          zlib-devel
 %patch3 -p1
 %patch4 -p1
 %patch5 -p1
+%patch6 -p1
 
 cp %{SOURCE200} %{SOURCE210} %{SOURCE10} %{SOURCE12} .
 
@@ -542,6 +546,10 @@ fi
 %{nginx_srcdir}/
 
 %changelog
+* Mon Oct 16 2023 Luboš Uhliarik <luhliari@redhat.com> - 1:1.22.1-2
+- Resolves: RHEL-12728 - nginx:1.22/nginx: HTTP/2: Multiple HTTP/2 enabled web
+  servers are vulnerable to a DDoS attack (Rapid Reset Attack)(CVE-2023-44487)
+
 * Thu Dec 01 2022 Luboš Uhliarik <luhliari@redhat.com> - 1:1.22.1-1
 - Resolves: #2112345 - nginx:1.22 for RHEL 8
 - add stream_geoip_module and stream_realip_module