Nginx server security configuration<\/p>\n
First, turn off SELinux
\nSecurity-Enhanced Linux (SELinux) is a Linux kernel feature that provides security policy protection mechanism supports access control.
\nHowever, SELinux brings additional security and the disproportionate use of complexity, cost is not high<\/p>\n
sed -i \/SELINUX=enforcing\/SELINUX=disabled\/ \/etc\/selinux\/config<\/p>\n
\/usr\/sbin\/sestatus -v # Check status<\/p>\n
Second, the least privilege allowed by zoning mount<\/p>\n
A separate partition on the server nginx directory.<\/p>\n
For example, create a new partition \/dev\/sda5 (first logical partition), and mounted at \/nginx.
\nMake sure \/nginx is noexec,nodev and nosetuid permission to mount<\/p>\n
The following is my \/etc\/fstab mount \/nginx information: LABEL=\/nginx \/nginx ext3 defaults,nosuid,noexec,nodev 1 2<\/p>\n
Note: You need to create a new partition using fdisk and mkfs.ext3 command.
\nThird, to strengthen the Linux security configuration \/etc\/sysctl.conf<\/p>\n
You can control and configure the Linux kernel by editing \/etc\/sysctl.conf, network settings<\/p>\n
# Avoid a smurf attack<\/p>\n
net.ipv4.icmp_echo_ignore_broadcasts = 1<\/p>\n
# Turn on protection for bad icmp error messages<\/p>\n
net.ipv4.icmp_ignore_bogus_error_responses = 1<\/p>\n
# Turn on syncookies for SYN flood attack protection<\/p>\n
net.ipv4.tcp_syncookies = 1<\/p>\n
# Turn on and log spoofed, source routed, and redirect packets<\/p>\n
net.ipv4.conf.all.log_martians = 1<\/p>\n
net.ipv4.conf.default.log_martians = 1<\/p>\n
# No source routed packets here<\/p>\n
net.ipv4.conf.all.accept_source_route = 0<\/p>\n
net.ipv4.conf.default.accept_source_route = 0<\/p>\n
# Turn on reverse path filtering<\/p>\n
net.ipv4.conf.all.rp_filter = 1<\/p>\n
net.ipv4.conf.default.rp_filter = 1<\/p>\n
# Make sure no one can alter the routing tables<\/p>\n
net.ipv4.conf.all.accept_redirects = 0<\/p>\n
net.ipv4.conf.default.accept_redirects = 0<\/p>\n
net.ipv4.conf.all.secure_redirects = 0<\/p>\n
net.ipv4.conf.default.secure_redirects = 0<\/p>\n
# Don\u2019t act as a router<\/p>\n
net.ipv4.ip_forward = 0<\/p>\n
net.ipv4.conf.all.send_redirects = 0<\/p>\n
net.ipv4.conf.default.send_redirects = 0<\/p>\n
# Turn on execshild<\/p>\n
kernel.exec-shield = 1<\/p>\n
kernel.randomize_va_space = 1<\/p>\n
# Tuen IPv6<\/p>\n
net.ipv6.conf.default.router_solicitations = 0<\/p>\n
net.ipv6.conf.default.accept_ra_rtr_pref = 0<\/p>\n
net.ipv6.conf.default.accept_ra_pinfo = 0<\/p>\n
net.ipv6.conf.default.accept_ra_defrtr = 0<\/p>\n
net.ipv6.conf.default.autoconf = 0<\/p>\n
net.ipv6.conf.default.dad_transmits = 0<\/p>\n
net.ipv6.conf.default.max_addresses = 1<\/p>\n
# Optimization for port usefor LBs<\/p>\n
# Increase system file descriptor limit<\/p>\n
fs.file-max = 65535<\/p>\n
# Allow for more PIDs (to reduce rollover problems); may break some programs 32768<\/p>\n
kernel.pid_max = 65536<\/p>\n
# Increase system IP port limits<\/p>\n
net.ipv4.ip_local_port_range = 2000 65000<\/p>\n
# Increase TCP max buffer size setable using setsockopt()<\/p>\n
net.ipv4.tcp_rmem = 4096 87380 8388608<\/p>\n
net.ipv4.tcp_wmem = 4096 87380 8388608<\/p>\n
# Increase Linux auto tuning TCP buffer limits<\/p>\n
# min, default, and max number of bytes to use<\/p>\n
# set max to at least 4MB, or higher if you use very high BDP paths<\/p>\n
# Tcp Windows etc<\/p>\n
net.core.rmem_max = 8388608<\/p>\n
net.core.wmem_max = 8388608<\/p>\n
net.core.netdev_max_backlog = 5000<\/p>\n
net.ipv4.tcp_window_scaling = 1<\/p>\n
Fourth, remove all unnecessary Nginx module<\/p>\n
You need to make the number of modules directly by compiling the source code Nginx minimized. By limiting access to only allow web server module to minimize risk.
\nYou can configure only install nginx modules you need. For example, disabling SSL and autoindex module you can execute the following command:<\/p>\n
.\/configure -without-http_autoindex_module -without-http_ssi_module
\nmake && make install<\/p>\n
Change nginx version name, edit the file \/h\/http\/ngx_http_header_filter_module.c?<\/p>\n
vim\u00a0 src\/http\/ngx_http_header_filter_module.c<\/p>\n
static char ngx_http_server_string[] = \u201cServer: nginx\u201d CRLF;<\/p>\n
static char ngx_http_server_full_string[] = \u201cServer: \u201d NGINX_VER CRLF;<\/p>\n
\/\/change to<\/p>\n
static char ngx_http_server_string[] = \u201cServer: Mohan Web Server\u201d CRLF;<\/p>\n
static char ngx_http_server_full_string[] = \u201cServer: Mohan Web Server\u201d CRLF;<\/p>\n
Close nginx version number display<\/p>\n
server_tokens off<\/p>\n
Fifth, based Iptables firewall restrictions<\/p>\n
The following firewall script block any addition to allowing:<\/p>\n
HTTP (TCP port 80) of a request from
\nICMP ping requests from
\nntp (port 123) requests output
\nsmtp (TCP port 25) request output<\/p>\n
Six control buffer overflow attacks<\/p>\n
Edit and set all clients buffer size limit is as follows:<\/p>\n
client_body_buffer_size\u00a0 1K;<\/p>\n
client_header_buffer_size 1k;<\/p>\n
client_max_body_size 1k;<\/p>\n
large_client_header_buffers 2 1k;<\/p>\n
client_body_buffer_size 1k (default 8k or 16k) This instruction can specify the buffer size of the connection request entity.
\nIf the value exceeds the specified buffer connection request, then the whole or part of the requesting entity will try to write a temporary file.
\nclient_header_buffer_size 1k\u00a0 directive specifies the client request buffer size of the head.
\nIn most cases a request header is not greater than 1k, but if there is a large cookie wap from the client that it may be greater than 1k,
\nNginx will assign it a larger buffer, this value can be set inside the large_client_header_buffers .
\nclient_max_body_size 1k- directive specifies the maximum allowable size of the client requesting entity connected, it appears in the Content-Length header field of the request.<\/p>\n
If the request is greater than the specified value, the client will receive a “Request Entity Too Large” (413) error. Remember, the browser does not know how to display the error.
\nlarge_client_header_buffers- specify the client number and size of some of the larger buffer request header use.
\nRequest a field can not be greater than the buffer size, if the client sends a relatively large head, nginx returns “Request URI too large” (414)
\nSimilarly, the head of the longest field of the request can not be greater than one buffer, otherwise the server will return “Bad request” (400). Separate buffer only when demand.
\nThe default buffer size for the operating system paging file size is usually 4k or 8k, if a connection request is ultimately state to keep- alive, it occupied the buffer will be freed.<\/p>\n
You also need to improve server performance control timeouts and disconnects the client. Edit as follows:<\/p>\n
client_body_timeout 10;
\nclient_header_timeout 10;
\nkeepalive_timeout 5 5;
\nsend_timeout 10;<\/p>\n
\u2022 client_body_timeout 10; – directive specifies the timeout request entity read. Here timeout refers to a requesting entity did not enter the reading step, if the connection after this time the client does not have any response, Nginx will return a “Request time out” (408) error.
\n\u2022 client_header_timeout 10; – directive specifies the client request header headline read timeout. Here timeout refers to a request header did not enter the reading step, if the connection after this time the client does not have any response, Nginx will return a “Request time out” (408) error.
\n\u2022 keepalive_timeout 5 5; – the first parameter specifies the timeout length of the client and server connections, over this time, the server will close the connection. The second parameter (optional) specifies the response header Keep-Alive: timeout = time value time, this value can make some browsers know when to close the connection to the server not repeat off if you do not specify this parameter , nginx does not send Keep-Alive header information in the response. (This does not refer to how a connection “Keep-Alive”) These two values ??of the parameters can be different.
\n\u2022 send_timeout 10; directive specifies the timeout is sent to the client after the response, Timeout refers not enter a complete state established, completed only two handshakes, more than this time if the client does not have any response, nginx will close the connection.<\/p>\n
Seven control concurrent connections<\/p>\n
You can use NginxHttpLimitZone module to restrict a specific session or a special case of concurrent connections IP addresses under. Edit nginx.conf:<\/p>\n
### Directive describes the zone, in which the session states are stored i.e. store in slimits. ###<\/p>\n
### 1m can handle 32000 sessions with 32 bytes\/session, set to 5m x 32000 session ###<\/p>\n
limit_zone slimits $binary_remote_addr 5m;<\/p>\n
### Control maximum number of simultaneous connections for one session i.e. ###<\/p>\n
### restricts the amount of connections from a single ip address ###<\/p>\n
limit_conn slimits 5<\/p>\n
The above represents the remote IP address to limit each client connection can not be open at the same time more than five.<\/p>\n
Eight, only allow access to our domain<\/p>\n
If the robot is just random scan all domain name servers, that reject the request. You must allow the configuration of the virtual domain or reverse proxy request. You do not use IP addresses to reject.<\/p>\n
if ($host !~ ^(test.in|www.test.in|images.test.in)$ ) {
\nreturn 444;
\n}<\/p>\n
Nine, to limit the request method available<\/p>\n
GET and POST are the Internet’s most commonly used method. The method of the Web server is defined in RFC 2616. If the Web server is not required to run all available methods, they should be disabled. The following command will filter only allows GET, HEAD and POST methods:<\/p>\n
## Only allow these request methods ##<\/p>\n
if ($request_method !~ ^(GET|HEAD|POST)$ ) {<\/p>\n
return 444;<\/p>\n
}<\/p>\n
## Do not accept DELETE, SEARCH and other methods ##<\/p>\n
More about HTTP method introduced<\/p>\n
\u2022 GET method is used to request,<\/p>\n
\u2022 HEAD method is the same, unless GET request to the server can not return the message body.<\/p>\n
\u2022 POST method can involve many things, such as storage or update data, or ordering products, or send e-mail by submitting the form. This is usually the use of server-side processing, such as PHP, Perl and Python scripts. If the file you want to upload and server processing the data, you must use this method.<\/p>\n
Ten, how to refuse a number of User-Agents?<\/p>\n
You can easily stop User-Agents, such as scanners, robotics and abuse your server spammers.<\/p>\n
## Block download agents ##<\/p>\n
if ($http_user_agent ~* LWP::Simple|BBBike|wget) {<\/p>\n
return 403;<\/p>\n
}<\/p>\n
Soso and the proper way to prevent robots:<\/p>\n
## Block some robots ##<\/p>\n
if ($http_user_agent ~* Sosospider|YodaoBot) {<\/p>\n
return 403;<\/p>\n
}<\/p>\n
XI prevent image hotlinking<\/p>\n
Pictures or HTML Daolian mean someone directly with your website address to display pictures on his website. The end result, you need to pay the extra cost of broadband. This is often in the forum and blog. I strongly recommend that you block and prevent hotlinking behavior.<\/p>\n
# Stop deep linking or hot linking<\/p>\n
location \/images\/ {<\/p>\n
valid_referers none blocked www.example.com example.com;<\/p>\n
if ($invalid_referer) {<\/p>\n
return\u00a0 403;<\/p>\n
}<\/p>\n
}<\/p>\n
For example: the redirect and display the specified image<\/p>\n
valid_referers blocked www.example.com example.com;<\/p>\n
valid_referers blocked www.example.com example.com;<\/p>\n
if ($invalid_referer) {<\/p>\n
rewrite ^\/images\/uploads.*\\.(gif|jpg|jpeg|png)$ http:\/\/www.examples.com\/banned.jpg last<\/p>\n
}<\/p>\n
Twelve, directory restrictions<\/p>\n
You can set access permissions on the specified directory. All websites directory should one configuration, allowing only access to the directory.
\nAccess by IP address restrictions
\nYou can restrict access by IP address directory \/ admin \/:<\/p>\n
ocation \/docs\/ {<\/p>\n
## block one workstation<\/p>\n
deny\u00a0\u00a0\u00a0 192.168.1.1;<\/p>\n
## allow anyone in 192.168.1.0\/24<\/p>\n
allow\u00a0 192.168.1.0\/24;<\/p>\n
## drop rest of the world<\/p>\n
deny\u00a0\u00a0\u00a0 all;<\/p>\n
}<\/p>\n
Via password protected directory, first create the password file and increase the “user” user<\/p>\n
mkdir \/usr\/local\/nginx\/conf\/.htpasswd\/<\/p>\n
htpasswd -c \/usr\/local\/nginx\/conf\/.htpasswd\/passwd user<\/p>\n
Edit nginx.conf, added need protected directories<\/p>\n
### Password Protect \/personal-images\/ and \/delta\/ directories ###<\/p>\n
location ~ \/(personal-images\/.*|delta\/.*) {<\/p>\n
auth_basic\u00a0 \u201cRestricted\u201d;<\/p>\n
auth_basic_user_file\u00a0 \/usr\/local\/nginx\/conf\/.htpasswd\/passwd;<\/p>\n
}<\/p>\n
Once the password file has been generated, you can also use the following command to allow access to the user increases<\/p>\n
htpasswd -s \/usr\/local\/nginx\/conf\/.htpasswd\/passwd userName<\/p>\n
Thirteen, Nginx SSL Configuration<\/p>\n
HTTP is a plain text protocol, which is open to passive surveillance. You should use SSL to encrypt your user content.
\nCreate SSL certificate, execute the following command:<\/p>\n
cd \/usr\/local\/nginx\/conf<\/p>\n
openssl genrsa -des3 -out server.key 1024<\/p>\n
openssl req -new -key server.key -out server.csr<\/p>\n
cp server.key server.key.org<\/p>\n
openssl rsa -in server.key.org -out server.key<\/p>\n
openssl x509 -req -days 365 -in server.csr -signkey server.key -out server.crt<\/p>\n
Edit nginx.conf press following updates:<\/p>\n
server {<\/p>\n
server_name example.com;<\/p>\n
listen 443;<\/p>\n
ssl on;<\/p>\n
ssl_certificate \/usr\/local\/nginx\/conf\/server.crt;<\/p>\n
ssl_certificate_key \/usr\/local\/nginx\/conf\/server.key;<\/p>\n
access_log \/usr\/local\/nginx\/logs\/ssl.access.log;<\/p>\n
error_log \/usr\/local\/nginx\/logs\/ssl.error.log;<\/p>\n
}<\/p>\n
Fourteen, Nginx and PHP Security Recommendations<\/p>\n
PHP is a popular scripting language on the server side. Edit \/etc\/php.ini file as follows:<\/p>\n
# Disallow dangerous functions<\/p>\n
disable_functions = phpinfo, system, mail, exec<\/p>\n
## Try to limit resources\u00a0 ##<\/p>\n
# Maximum execution time of each script, in seconds<\/p>\n
max_execution_time = 30<\/p>\n
# Maximum amount of time each script may spend parsing request data<\/p>\n
max_input_time = 60<\/p>\n
# Maximum amount of memory a script may consume (8MB)<\/p>\n
memory_limit = 8M<\/p>\n
# Maximum size of POST data that PHP will accept.<\/p>\n
post_max_size = 8M<\/p>\n
# Whether to allow HTTP file uploads.<\/p>\n
file_uploads = Off<\/p>\n
# Maximum allowed size for uploaded files.<\/p>\n
upload_max_filesize = 2M<\/p>\n
# Do not expose PHP error messages to external users<\/p>\n
display_errors = Off<\/p>\n
# Turn on safe mode<\/p>\n
safe_mode = On<\/p>\n
# Only allow access to executables in isolated directory<\/p>\n
safe_mode_exec_dir = php-required-executables-path<\/p>\n
# Limit external access to PHP environment<\/p>\n
safe_mode_allowed_env_vars = PHP_<\/p>\n
# Restrict PHP information leakage<\/p>\n
expose_php = Off<\/p>\n
# Log all errors<\/p>\n
log_errors = On<\/p>\n
# Do not register globals for input data<\/p>\n
register_globals = Off<\/p>\n
# Minimize allowable PHP post size<\/p>\n
post_max_size = 1K<\/p>\n
# Ensure PHP redirects appropriately<\/p>\n
cgi.force_redirect = 0<\/p>\n
# Disallow uploading unless necessary<\/p>\n
# Enable SQL safe mode<\/p>\n
sql.safe_mode = On<\/p>\n
# Avoid Opening remote files<\/p>\n
allow_url_fopen = Off<\/p>\n
Fifth, if possible, let Nginx run in a chroot jail<\/p>\n
The nginx placed in a chroot jail to reduce the potential for illegal entry into other directories. You can use the traditional and nginx installed with chroot. If possible, that use FreeBSD jails, Xen, OpenVZ virtualization container concept.<\/p>\n
XVI firewall level limits the number of connections for each IP<\/p>\n
Network server must monitor connections and connection limits per second. PF and Iptales are able to enter your nginx server before the end user to block access.
\nLinux Iptables: limit the number of connections for each Nginx
\nfollowing example will prevent from a single IP connection of more than 15 the number of ports 80, 60 seconds.<\/p>\n
\/sbin\/iptables -A INPUT -p tcp \u2013dport 80 -i eth0 -m state \u2013state NEW -m recent \u2013set<\/p>\n
\/sbin\/iptables -A INPUT -p tcp \u2013dport 80 -i eth0 -m state \u2013state NEW -m recent \u2013update \u2013seconds 60\u00a0 \u2013hitcount 15 -j DROP<\/p>\n
service iptables save<\/p>\n
According to your specific situation to set the connection limit.<\/p>\n
XVII configure the operating system to protect Web servers<\/p>\n
Like the above described start SELinux Correct set permissions \/nginx document root directory.
\nNginx running in user nginx. But the root directory (\/ nginx or \/usr\/local\/nginx\/html\/) should not be set, or the user belongs to the user nginx nginx writable.
\nFind the error file permissions can use the following command:<\/p>\n
find \/nginx -user nginx<\/p>\n
find \/usr\/local\/nginx\/html -user nginx<\/p>\n
Make sure you are more ownership of the root or other users, a typical permission settings \/usr\/local\/nginx\/html\/<\/p>\n
ls -l \/usr\/local\/nginx\/html\/<\/p>\n
Sample output:<\/p>\n
-rw-r-r- 1 root root 925 Jan 3 00:50 error4xx.html<\/p>\n
-rw-r-r- 1 root root 52 Jan 3 10:00 error5xx.html<\/p>\n
-rw-r-r- 1 root root 134 Jan 3 00:52 index.html<\/p>\n
You must delete the backup files from the vi or another text editor to create:<\/p>\n
find \/nginx -name \u2018.?*\u2019 -not -name .ht* -or -name \u2018*~\u2019 -or -name \u2018*.bak*\u2019 -or -name \u2018*.old*\u2019<\/p>\n
find \/usr\/local\/nginx\/html\/ -name \u2018.?*\u2019 -not -name .ht* -or -name \u2018*~\u2019 -or -name \u2018*.bak*\u2019 -or -name \u2018*.old*\u2019<\/p>\n
To delete these files by -delete option to find command.<\/p>\n
Eighth, the outgoing connections limit Nginx<\/p>\n
Hackers can use tools such as wget download your local file server. Iptables from using nginx user to block outgoing connections. ipt_owner module tries to match the creator of locally generated packets. The following example allows only users 80 user connections outside.<\/p>\n
\/sbin\/iptables -A OUTPUT -o eth0 -m owner \u2013uid-owner vivek -p tcp \u2013dport 80 -m state \u2013state NEW,ESTABLISHED\u00a0 -j ACCEPT<\/p>\n
With the above configuration, your nginx server is already very safe and you can publish web pages. However, you should also find more information on security settings according to your site procedures. For example, wordpress or a third-party program.<\/p>\n","protected":false},"excerpt":{"rendered":"
Nginx server security configuration<\/p>\n
First, turn off SELinux Security-Enhanced Linux (SELinux) is a Linux kernel feature that provides security policy protection mechanism supports access control. However, SELinux brings additional security and the disproportionate use of complexity, cost is not high<\/p>\n
sed -i \/SELINUX=enforcing\/SELINUX=disabled\/ \/etc\/selinux\/config<\/p>\n
\/usr\/sbin\/sestatus -v # Check status<\/p>\n
Second, the least privilege allowed by […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[70],"tags":[],"_links":{"self":[{"href":"https:\/\/mohan.sg\/index.php?rest_route=\/wp\/v2\/posts\/5576"}],"collection":[{"href":"https:\/\/mohan.sg\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/mohan.sg\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/mohan.sg\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/mohan.sg\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=5576"}],"version-history":[{"count":1,"href":"https:\/\/mohan.sg\/index.php?rest_route=\/wp\/v2\/posts\/5576\/revisions"}],"predecessor-version":[{"id":5577,"href":"https:\/\/mohan.sg\/index.php?rest_route=\/wp\/v2\/posts\/5576\/revisions\/5577"}],"wp:attachment":[{"href":"https:\/\/mohan.sg\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=5576"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/mohan.sg\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=5576"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/mohan.sg\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=5576"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}