﻿id	summary	reporter	owner	description	type	status	priority	milestone	component	version	resolution	keywords	cc	uname	nginx_version
1812	NGINX does not reply with HTTP Headers on broken request line	archmalet@…		"NGINX does reply without HTTP Response Headers when there is a newline character in the HTTP request line before the HTTP version.

With an example valid request (NGINX listens on port 8080 here):

{{{
GET /foobar HTTP/1.1
Host: localhost:8080
User-Agent: A user agent
Pragma: no-cache
Cache-Control: no-cache

}}}

NGINX responds with:
{{{
HTTP/1.1 404 Not Found
Server: nginx/1.17.1
Date: Mon, 15 Jul 2019 15:59:40 GMT
Content-Type: text/html
Content-Length: 153
Connection: keep-alive

<html>
<head><title>404 Not Found</title></head>
<body>
<center><h1>404 Not Found</h1></center>
<hr><center>nginx/1.17.1</center>
</body>
</html>
}}}

With a newline in the request line like in the following example:
{{{
GET /foobar
HTTP/1.1
Host: localhost:8080
User-Agent: A user agent
Pragma: no-cache
Cache-Control: no-cache

}}}

the response (note that the response headers are missing here) is:
{{{
<html>
<head><title>404 Not Found</title></head>
<body>
<center><h1>404 Not Found</h1></center>
<hr><center>nginx/1.17.1</center>
</body>
</html>
}}}

Putting the newline inside the HTTP version like in the following request does return a 400 Bad Request with headers
{{{
GET /foobar HTT
P/1.1
Host: localhost:8080
User-Agent: A user agent
Pragma: no-cache
Cache-Control: no-cache

}}}

I'm guessing that the newline character before the HTTP version messes up the state machine of HTTP Request parsing in NGINX.
"	defect	closed	minor		nginx-core	1.17.x	invalid				"nginx version: nginx/1.17.1
built by gcc 6.3.0 20170516 (Debian 6.3.0-18+deb9u1)
built with OpenSSL 1.1.0j  20 Nov 2018
TLS SNI support enabled
configure arguments: --prefix=/etc/nginx --sbin-path=/usr/sbin/nginx --modules-path=/usr/lib/nginx/modules --conf-path=/etc/nginx/nginx.conf --error-log-path=/var/log/nginx/error.log --http-log-path=/var/log/nginx/access.log --pid-path=/var/run/nginx.pid --lock-path=/var/run/nginx.lock --http-client-body-temp-path=/var/cache/nginx/client_temp --http-proxy-temp-path=/var/cache/nginx/proxy_temp --http-fastcgi-temp-path=/var/cache/nginx/fastcgi_temp --http-uwsgi-temp-path=/var/cache/nginx/uwsgi_temp --http-scgi-temp-path=/var/cache/nginx/scgi_temp --user=nginx --group=nginx --with-compat --with-file-aio --with-threads --with-http_addition_module --with-http_auth_request_module --with-http_dav_module --with-http_flv_module --with-http_gunzip_module --with-http_gzip_static_module --with-http_mp4_module --with-http_random_index_module --with-http_realip_module --with-http_secure_link_module --with-http_slice_module --with-http_ssl_module --with-http_stub_status_module --with-http_sub_module --with-http_v2_module --with-mail --with-mail_ssl_module --with-stream --with-stream_realip_module --with-stream_ssl_module --with-stream_ssl_preread_module --with-cc-opt='-g -O2 -fdebug-prefix-map=/data/builder/debuild/nginx-1.17.1/debian/debuild-base/nginx-1.17.1=. -fstack-protector-strong -Wformat -Werror=format-security -Wp,-D_FORTIFY_SOURCE=2 -fPIC' --with-ld-opt='-Wl,-z,relro -Wl,-z,now -Wl,--as-needed -pie'
"
