diff --git a/0008-CVE-2023-44487-HTTP-2-per-iteration-stream-handling.patch b/0008-CVE-2023-44487-HTTP-2-per-iteration-stream-handling.patch new file mode 100644 index 0000000..1c02e49 --- /dev/null +++ b/0008-CVE-2023-44487-HTTP-2-per-iteration-stream-handling.patch @@ -0,0 +1,74 @@ +From b6aa9504cdfb6391d895dcbddc87b9260ea6968c Mon Sep 17 00:00:00 2001 +From: =?UTF-8?q?Lubo=C5=A1=20Uhliarik?= +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 3611a2e..291677a 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; +@@ -1320,6 +1321,14 @@ 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) +@@ -1385,6 +1394,12 @@ 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 3492297..6a7aaa6 100644 +--- a/src/http/v2/ngx_http_v2.h ++++ b/src/http/v2/ngx_http_v2.h +@@ -125,6 +125,8 @@ 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; diff --git a/nginx.spec b/nginx.spec index 896d88b..286c7b9 100644 --- a/nginx.spec +++ b/nginx.spec @@ -41,7 +41,7 @@ Name: nginx Epoch: 1 Version: 1.20.1 -Release: 14%{?dist} +Release: 15%{?dist} Summary: A high performance web server and reverse proxy server # BSD License (two clause) @@ -91,6 +91,9 @@ Patch5: 0006-Fix-ALPACA-security-issue.patch # downstream patch for RHEL - https://bugzilla.redhat.com/show_bug.cgi?id=2028781 Patch6: 0007-Enable-TLSv1.3-by-default.patch +# security patch - https://issues.redhat.com/browse/RHEL-12518 +Patch7: 0008-CVE-2023-44487-HTTP-2-per-iteration-stream-handling.patch + BuildRequires: make BuildRequires: gcc BuildRequires: gnupg2 @@ -602,6 +605,10 @@ fi %changelog +* Mon Oct 16 2023 Luboš Uhliarik - 1:1.20.1-15 +- Resolves: RHEL-12518 - nginx: HTTP/2: Multiple HTTP/2 enabled web servers are + vulnerable to a DDoS attack (Rapid Reset Attack) (CVE-2023-44487) + * Thu Nov 24 2022 Luboš Uhliarik - 1:1.20.1-14 - Resolves: #2086527 - Fix logrotate config and nginx log dir permissions