Security tuning

BunkerWeb offers many security features that you can configure with settings. Even if the default values of settings ensure a minimal "security by default", we strongly recommend you tune them. By doing so you will be able to ensure the security level of your choice but also manage false positives.

Other settings

This section only focuses on security tuning, see the settings section of the documentation for other settings.

Overview and order of the core security plugins

HTTP protocol

Deny status code

STREAM support

The first thing to define is the kind of action to do when a client access is denied. You can control the action with the DENY_HTTP_STATUS setting which allows the following values :

• 403 : send a "classical" Forbidden HTTP status code (a web page or custom content will be displayed)
• 444 : close the connection (no web page or custom content will be displayed)

The default value is 403 and we suggest you set it to 444 only if you already fixed a lot of false positive, you are familiar with BunkerWeb and want a higher level of security.

When using stream mode, value is ignored and always set to 444 with effect of closing the connection.

Default server

STREAM support

In the HTTP protocol, the Host header is used to determine which server the client wants to send the request to. That header is facultative and may be missing from the request or can be set as an unknown value. This is a common case, a lot of bots are scanning the Internet and are trying to exploit services or simply doing some fingerprinting.

You can disable any request containing undefined or unknown Host value by setting DISABLE_DEFAULT_SERVER to yes (default : no). Please note that clients won't even receive a response, the TCP connection will be closed (using the special 444 status code of NGINX).

Allowed methods

STREAM support

You can control the allowed HTTP methods by listing them (separated with "|") in the ALLOWED_METHODS setting (default : GET|POST|HEAD). Clients sending a method which is not listed will get a "405 - Method Not Allowed".

Max sizes

STREAM support

You can control the maximum body size with the MAX_CLIENT_SIZE setting (default : 10m). See here for accepted values. You can use the special value 0 to allow a body of infinite size (not recommended).

Serve files

STREAM support

To disable serving files from the www folder, you can set SERVE_FILES to no (default : yes). The value no is recommended if you use BunkerWeb as a reverse proxy.

Headers

STREAM support

Headers are very important when it comes to HTTP security. While some of them might be too verbose, others' verbosity will need to be increased, especially on the client-side.

Remove headers

STREAM support

You can automatically remove verbose headers in the HTTP responses by using the REMOVE_HEADERS setting (default : Server X-Powered-By X-AspNet-Version X-AspNetMvc-Version).

Keep upstream headers

STREAM support

You can automatically keep headers from upstream servers and prevent BunkerWeb from overriding them in the HTTP responses by using the KEEP_UPSTREAM_HEADERS setting (default : Content-Security-Policy Permissions-Policy Feature-Policy X-Frame-Options). A special value * is available to keep all headers. List of headers to keep must be separated with a space. Note that if the header is not present in the upstream response, it will be added by BunkerWeb.

Cookies

STREAM support

When it comes to cookies security, we can use the following flags :

• HttpOnly : disable any access to the cookie from Javascript using document.cookie
• SameSite : policy when requests come from third-party websites
• Secure : only send cookies on HTTPS request

Cookie flags can be overridden with values of your choice by using the COOKIE_FLAGS setting (default : * HttpOnly SameSite=Lax). See here for accepted values.

The Secure flag can be automatically added if HTTPS is used by using the COOKIE_AUTO_SECURE_FLAG setting (default : yes). The value no is not recommended unless you know what you're doing.

Security headers

STREAM support

Various security headers are available and most of them can be set using BunkerWeb settings. Here is the list of headers, the corresponding setting and default value :

Header	Setting	Default
Content-Security-Policy	CONTENT_SECURITY_POLICY	object-src 'none'; frame-src 'self'; child-src 'self'; form-action 'self'; frame-ancestors 'self';
Strict-Transport-Security	STRICT_TRANSPORT_SECURITY	max-age=31536000
Referrer-Policy	REFERRER_POLICY	strict-origin-when-cross-origin
Permissions-Policy	PERMISSIONS_POLICY	accelerometer=(), ambient-light-sensor=(), autoplay=(), battery=(), camera=(), cross-origin-isolated=(), display-capture=(), document-domain=(), encrypted-media=(), execution-while-not-rendered=(), execution-while-out-of-viewport=(), fullscreen=(), geolocation=(), gyroscope=(), hid=(), idle-detection=(), magnetometer=(), microphone=(), midi=(), navigation-override=(), payment=(), picture-in-picture=(), publickey-credentials-get=(), screen-wake-lock=(), serial=(), usb=(), web-share=(), xr-spatial-tracking=()
Feature-Policy	FEATURE_POLICY	accelerometer 'none'; ambient-light-sensor 'none'; autoplay 'none'; battery 'none'; camera 'none'; display-capture 'none'; document-domain 'none'; encrypted-media 'none'; execution-while-not-rendered 'none'; execution-while-out-of-viewport 'none'; fullscreen 'none'; 'none'; geolocation 'none'; gyroscope 'none'; layout-animation 'none'; legacy-image-formats 'none'; magnetometer 'none'; microphone 'none'; midi 'none'; navigation-override 'none'; payment 'none'; picture-in-picture 'none'; publickey-credentials-get 'none'; speaker-selection 'none'; sync-xhr 'none'; unoptimized-images 'none'; unsized-media 'none'; usb 'none'; screen-wake-lock 'none'; web-share 'none'; xr-spatial-tracking 'none';
X-Frame-Options	X_FRAME_OPTIONS	SAMEORIGIN
X-Content-Type-Options	X_CONTENT_TYPE_OPTIONS	nosniff
X-XSS-Protection	X_XSS_PROTECTION	1; mode=block

CORS

STREAM support

Cross-Origin Resource Sharing lets you manage how your service can be contacted from different origins. Please note that you will have to allow the OPTIONS HTTP method using the ALLOWED_METHODS if you want to enable it (more info here). Here is the list of settings related to CORS :

Setting	Default	Context	Multiple	Description
USE_CORS	no	multisite	no	Use CORS
CORS_ALLOW_ORIGIN	*	multisite	no	Allowed origins to make CORS requests : PCRE regex or *.
CORS_EXPOSE_HEADERS	Content-Length,Content-Range	multisite	no	Value of the Access-Control-Expose-Headers header.
CORS_MAX_AGE	86400	multisite	no	Value of the Access-Control-Max-Age header.
CORS_ALLOW_CREDENTIALS	no	multisite	no	Send the Access-Control-Allow-Credentials header.
CORS_ALLOW_METHODS	GET, POST, OPTIONS	multisite	no	Value of the Access-Control-Allow-Methods header.
CORS_ALLOW_HEADERS	DNT,User-Agent,X-Requested-With,If-Modified-Since,Cache-Control,Content-Type,Range	multisite	no	Value of the Access-Control-Allow-Headers header.
CORS_DENY_REQUEST	yes	multisite	no	Deny request and don't send it to backend if Origin is not allowed.

Here is some examples of possible values for CORS_ALLOW_ORIGIN setting :

• * will allow all origin
• ^https://www\.example\.com$ will allow https://www.example.com
• ^https://.+\.example.com$ will allow any origins when domain ends with .example.com
• ^https://(www\.example1\.com|www\.example2\.com)$ will allow both https://www.example1.com and https://www.example2.com
• ^https?://www\.example\.com$ will allow both https://www.example.com and http://www.example.com

HTTPS / SSL/TLS

Besides the HTTPS / SSL/TLS configuration, the following settings related to HTTPS / SSL/TLS can be set :

Setting	Default	Description
REDIRECT_HTTP_TO_HTTPS	no	When set to yes, will redirect every HTTP request to HTTPS even if BunkerWeb is not configured with HTTPS.
AUTO_REDIRECT_HTTP_TO_HTTPS	yes	When set to yes, will redirect every HTTP request to HTTPS only if BunkerWeb is configured with HTTPS.
SSL_PROTOCOLS	TLSv1.2 TLSv1.3	List of supported SSL/TLS protocols when SSL is enabled.
HTTP2	yes	When set to yes, will enable HTTP2 protocol support when using HTTPS.
LISTEN_HTTP	yes	When set to no, BunkerWeb will not listen for HTTP requests. Useful if you want HTTPS only for example.

Let's Encrypt

STREAM support

BunkerWeb comes with automatic Let's Encrypt certificate generation and renewal. This is the easiest way of getting HTTPS / SSL/TLS working out of the box for public-facing web applications. Please note that you will need to set up proper DNS A record(s) for each of your domains pointing to your public IP(s) where BunkerWeb is accessible.

Here is the list of related settings :

Setting	Default	Description
AUTO_LETS_ENCRYPT	no	When set to yes, HTTPS / SSL/TLS will be enabled with automatic certificate generation and renewal from Let's Encrypt.
EMAIL_LETS_ENCRYPT	contact@{FIRST_SERVER}	Email to use when generating certificates. Let's Encrypt will send notifications to that email like certificate expiration.
USE_LETS_ENCRYPT_STAGING	no	When set to yes, the staging server of Let's Encrypt will be used instead of the production one. Useful when doing tests to avoid being "blocked" due to limits.

Full Let's Encrypt automation is fully working with stream mode as long as you open the 80/tcp port from the outside. Please note that you will need to use the LISTEN_STREAM_PORT_SSL setting in order to choose your listening SSL/TLS port.

Let's Encrypt DNS (PRO)

STREAM support

The Let's Encrypt DNS plugin facilitates the automatic creation, renewal, and configuration of Let's Encrypt certificates using DNS challenges.

This plugin offers seamless integration with various DNS providers for streamlined certificate management.

List of features

• Automatic creation and renewal of Let's Encrypt certificates
• Integration with DNS providers for DNS challenges
• Generate wildcard certificates
• Configuration options for customization and flexibility

Settings of the Let's Encrypt DNS plugin

Setting	Default	Context	Multiple	Description
AUTO_LETS_ENCRYPT_DNS	no	multisite	no	Set to yes to enable automatic certificate creation and renewal using DNS challenges.
LETS_ENCRYPT_DNS_EMAIL		multisite	no	Email address for Let's Encrypt notifications.
USE_LETS_ENCRYPT_DNS_STAGING	no	multisite	no	Set to yes to use Let's Encrypt staging server.
LETS_ENCRYPT_DNS_PROVIDER		multisite	no	DNS provider for Let's Encrypt DNS challenges.
USE_LETS_ENCRYPT_DNS_WILDCARD	no	multisite	no	Set to yes to automatically generate wildcard domains in certificates.
LETS_ENCRYPT_DNS_PROPAGATION	default	multisite	no	Time in seconds to wait for DNS propagation.
LETS_ENCRYPT_DNS_CREDENTIAL_ITEM		multisite	yes	Credential item for Let's Encrypt DNS provider that contains required credentials.

Information and behavior

• The LETS_ENCRYPT_DNS_CREDENTIAL_ITEM setting is a multiple setting and can be used to set multiple items for the DNS provider. The items will be saved as a cache file and Certbot will read the credentials from it.

• If no LETS_ENCRYPT_DNS_PROPAGATION setting is set, the provider's default propagation time will be used.

Available DNS Providers

Provider	Description	Mandatory Settings	Link(s)
cloudflare	Cloudflare DNS provider	dns_cloudflare_api_token	Documentation
digitalocean	DigitalOcean DNS provider	dns_digitalocean_token	Documentation
google	Google Cloud DNS provider	project_id, private_key_id, private_key, client_email, client_email, client_x509_cert_url	Documentation
linode	Linode DNS provider	dns_linode_key	Documentation
ovh	OVH DNS provider	dns_ovh_application_key, dns_ovh_application_secret, dns_ovh_consumer_key	Documentation
rfc2136	RFC 2136 DNS provider	dns_rfc2136_server, dns_rfc2136_name, dns_rfc2136_secret	Documentation
route53	Amazon Route 53 DNS provider	aws_access_key_id, aws_secret_access_key	Documentation
scaleway	Scaleway DNS provider	dns_scaleway_application_token	Documentation

Custom certificate

STREAM support

If you want to use your own certificates, here is the list of related settings :

Setting	Default	Context	Multiple	Description
USE_CUSTOM_SSL	no	multisite	no	Use custom HTTPS / SSL/TLS certificate.
CUSTOM_SSL_CERT		multisite	no	Full path of the certificate or bundle file (must be readable by the scheduler).
CUSTOM_SSL_KEY		multisite	no	Full path of the key file (must be readable by the scheduler).

When USE_CUSTOM_SSL is set to yes, BunkerWeb will check every day if the custom certificate specified in CUSTOM_SSL_CERT is modified and will reload NGINX if that's the case.

When using stream mode, you will need to use the LISTEN_STREAM_PORT_SSL setting in order to choose your listening SSL/TLS port.

Self-signed

STREAM support

If you want to quickly test HTTPS / SSL/TLS for staging/dev environment you can configure BunkerWeb to generate self-signed certificates, here is the list of related settings :

Setting	Default	Description
GENERATE_SELF_SIGNED_SSL	no	When set to yes, HTTPS / SSL/TLS will be enabled with automatic self-signed certificate generation and renewal from Let's Encrypt.
SELF_SIGNED_SSL_EXPIRY	365	Number of days for the certificate expiration (-days value used with openssl).
SELF_SIGNED_SSL_SUBJ	/CN=www.example.com/	Certificate subject to use (-subj value used with openssl).

When using stream mode, you will need to use the LISTEN_STREAM_PORT_SSL setting in order to choose your listening SSL/TLS port.

ModSecurity

STREAM support

ModSecurity is integrated and enabled by default alongside the OWASP Core Rule Set within BunkerWeb. Here is the list of related settings :

Setting	Default	Description
USE_MODSECURITY	yes	When set to yes, ModSecurity will be enabled.
USE_MODSECURITY_CRS	yes	When set to yes and USE_MODSECURITY is also set to yes, the OWASP Core Rule Set will be loaded.
MODSECURITY_CRS_VERSION	3	Version of the OWASP Core Rule Set to use.

ModSecurity and the OWASP Core Rule Set

We strongly recommend keeping both ModSecurity and the OWASP Core Rule Set enabled. The only downsides are the false positives that may occur. But they can be fixed with some efforts and the CRS team maintains a list of exclusions for common applications (e.g., WordPress, Nextcloud, Drupal, Cpanel, ...).

You can choose between the following versions of the OWASP Core Rule Set :

• 3 : The version v3.3.5 of the OWASP Core Rule Set (default)
• 4 : The version v4.0.0 of the OWASP Core Rule Set

Custom configurations

Tuning ModSecurity and the CRS can be done using custom configurations :

• modsec-crs : before the OWASP Core Rule Set is loaded
• modsec : after the OWASP Core Rule Set is loaded (also used if CRS is not loaded)

For example, you can add a custom configuration with type modsec-crs to add CRS exclusions :

SecAction \
 "id:900130,\
  phase:1,\
  nolog,\
  pass,\
  t:none,\
  setvar:tx.crs_exclusions_wordpress=1"

You can also add a custom configuration with type modsec to update loaded CRS rules :

SecRule REQUEST_FILENAME "/wp-admin/admin-ajax.php" "id:1,ctl:ruleRemoveByTag=attack-xss,ctl:ruleRemoveByTag=attack-rce"
SecRule REQUEST_FILENAME "/wp-admin/options.php" "id:2,ctl:ruleRemoveByTag=attack-xss"
SecRule REQUEST_FILENAME "^/wp-json/yoast" "id:3,ctl:ruleRemoveById=930120"

Bad behavior

STREAM support

When attackers search for and/or exploit vulnerabilities they might generate some "suspicious" HTTP status codes that a "regular" user won’t generate within a period of time. If we detect that kind of behavior we can ban the offending IP address and force the attacker to come up with a new one.

That kind of security measure is implemented and enabled by default in BunkerWeb and is called "Bad behavior". Here is the list of the related settings :

Setting	Default	Description
USE_BAD_BEHAVIOR	yes	When set to yes, the Bad behavior feature will be enabled.
BAD_BEHAVIOR_STATUS_CODES	400 401 403 404 405 429 444	List of HTTP status codes considered as "suspicious".
BAD_BEHAVIOR_BAN_TIME	86400	The duration time (in seconds) of a ban when a client reached the threshold.
BAD_BEHAVIOR_THRESHOLD	10	Maximum number of "suspicious" HTTP status codes within the time period.
BAD_BEHAVIOR_COUNT_TIME	60	Period of time during which we count "suspicious" HTTP status codes.

In other words, with the default values, if a client generates more than 10 status codes from the list 400 401 403 404 405 429 444 within 60 seconds their IP address will be banned for 86400 seconds.

When using stream mode, only the 444 status code will count as "bad".

Antibot

STREAM support

Attackers will certainly use automated tools to exploit/find some vulnerabilities in your web applications. One countermeasure is to challenge the users to detect if they look like a bot. If the challenge is solved, we consider the client as "legitimate" and they can access the web application.

That kind of security is implemented but not enabled by default in BunkerWeb and is called "Antibot". Here is the list of supported challenges :

• Cookie : send a cookie to the client, we expect to get the cookie back on other requests
• Javascript : force a client to solve a computation challenge using Javascript
• Captcha : force the client to solve a classical captcha (no external dependencies)
• hCaptcha : force the client to solve a captcha from hCaptcha
• reCAPTCHA : force the client to get a minimum score with Google reCAPTCHA
• Turnstile : enforce rate limiting and access control for APIs and web applications using various mechanisms with Coudflare Turnstile

Here is the list of related settings :

Setting	Default	Context	Multiple	Description
USE_ANTIBOT	no	multisite	no	Activate antibot feature.
ANTIBOT_URI	/challenge	multisite	no	Unused URI that clients will be redirected to to solve the challenge.
ANTIBOT_RECAPTCHA_SCORE	0.7	multisite	no	Minimum score required for reCAPTCHA challenge.
ANTIBOT_RECAPTCHA_SITEKEY		multisite	no	Sitekey for reCAPTCHA challenge.
ANTIBOT_RECAPTCHA_SECRET		multisite	no	Secret for reCAPTCHA challenge.
ANTIBOT_HCAPTCHA_SITEKEY		multisite	no	Sitekey for hCaptcha challenge.
ANTIBOT_HCAPTCHA_SECRET		multisite	no	Secret for hCaptcha challenge.
ANTIBOT_TURNSTILE_SITEKEY		multisite	no	Sitekey for Turnstile challenge.
ANTIBOT_TURNSTILE_SECRET		multisite	no	Secret for Turnstile challenge.
ANTIBOT_TIME_RESOLVE	60	multisite	no	Maximum time (in seconds) clients have to resolve the challenge. Once this time has passed, a new challenge will be generated.
ANTIBOT_TIME_VALID	86400	multisite	no	Maximum validity time of solved challenges. Once this time has passed, clients will need to resolve a new one.

Please note that antibot feature is using a cookie to maintain a session with clients. If you are using BunkerWeb in a clustered environment, you will need to set the SESSIONS_SECRET and SESSIONS_NAME settings to another value than the default one (which is random). You will find more info about sessions here.

Blacklisting, whitelisting and greylisting

The blacklisting security feature is very easy to understand : if a specific criteria is met, the client will be banned. As for the whitelisting, it's the exact opposite : if a specific criteria is met, the client will be allowed and no additional security check will be done. Whereas for the greylisting : if a specific criteria is met, the client will be allowed but additional security checks will be done.

You can configure blacklisting, whitelisting and greylisting at the same time. If that's the case, note that whitelisting is executed before blacklisting and greylisting : even if a criteria is true for all of them, the client will be whitelisted.

Blacklisting

STREAM support

You can use the following settings to set up blacklisting :

Setting	Default	Context	Multiple	Description
USE_BLACKLIST	yes	multisite	no	Activate blacklist feature.
BLACKLIST_IP		multisite	no	List of IP/network, separated with spaces, to block.
BLACKLIST_IP_URLS	https://www.dan.me.uk/torlist/?exit	global	no	List of URLs, separated with spaces, containing bad IP/network to block.
BLACKLIST_RDNS_GLOBAL	yes	multisite	no	Only perform RDNS blacklist checks on global IP addresses.
BLACKLIST_RDNS	.shodan.io .censys.io	multisite	no	List of reverse DNS suffixes, separated with spaces, to block.
BLACKLIST_RDNS_URLS		global	no	List of URLs, separated with spaces, containing reverse DNS suffixes to block.
BLACKLIST_ASN		multisite	no	List of ASN numbers, separated with spaces, to block.
BLACKLIST_ASN_URLS		global	no	List of URLs, separated with spaces, containing ASN to block.
BLACKLIST_USER_AGENT		multisite	no	List of User-Agent (PCRE regex), separated with spaces, to block.
BLACKLIST_USER_AGENT_URLS	https://raw.githubusercontent.com/mitchellkrogza/nginx-ultimate-bad-bot-blocker/master/_generator_lists/bad-user-agents.list	global	no	List of URLs, separated with spaces, containing bad User-Agent to block.
BLACKLIST_URI		multisite	no	List of URI (PCRE regex), separated with spaces, to block.
BLACKLIST_URI_URLS		global	no	List of URLs, separated with spaces, containing bad URI to block.
BLACKLIST_IGNORE_IP		multisite	no	List of IP/network, separated with spaces, to ignore in the blacklist.
BLACKLIST_IGNORE_IP_URLS		global	no	List of URLs, separated with spaces, containing IP/network to ignore in the blacklist.
BLACKLIST_IGNORE_RDNS		multisite	no	List of reverse DNS suffixes, separated with spaces, to ignore in the blacklist.
BLACKLIST_IGNORE_RDNS_URLS		global	no	List of URLs, separated with spaces, containing reverse DNS suffixes to ignore in the blacklist.
BLACKLIST_IGNORE_ASN		multisite	no	List of ASN numbers, separated with spaces, to ignore in the blacklist.
BLACKLIST_IGNORE_ASN_URLS		global	no	List of URLs, separated with spaces, containing ASN to ignore in the blacklist.
BLACKLIST_IGNORE_USER_AGENT		multisite	no	List of User-Agent (PCRE regex), separated with spaces, to ignore in the blacklist.
BLACKLIST_IGNORE_USER_AGENT_URLS		global	no	List of URLs, separated with spaces, containing User-Agent to ignore in the blacklist.
BLACKLIST_IGNORE_URI		multisite	no	List of URI (PCRE regex), separated with spaces, to ignore in the blacklist.
BLACKLIST_IGNORE_URI_URLS		global	no	List of URLs, separated with spaces, containing URI to ignore in the blacklist.

When using stream mode, only IP, RDNS and ASN checks will be done.

Greylisting

STREAM support

You can use the following settings to set up greylisting :

Setting	Default	Context	Multiple	Description
USE_GREYLIST	no	multisite	no	Activate greylist feature.
GREYLIST_IP		multisite	no	List of IP/network, separated with spaces, to put into the greylist.
GREYLIST_IP_URLS		global	no	List of URLs, separated with spaces, containing good IP/network to put into the greylist.
GREYLIST_RDNS_GLOBAL	yes	multisite	no	Only perform RDNS greylist checks on global IP addresses.
GREYLIST_RDNS		multisite	no	List of reverse DNS suffixes, separated with spaces, to put into the greylist.
GREYLIST_RDNS_URLS		global	no	List of URLs, separated with spaces, containing reverse DNS suffixes to put into the greylist.
GREYLIST_ASN		multisite	no	List of ASN numbers, separated with spaces, to put into the greylist.
GREYLIST_ASN_URLS		global	no	List of URLs, separated with spaces, containing ASN to put into the greylist.
GREYLIST_USER_AGENT		multisite	no	List of User-Agent (PCRE regex), separated with spaces, to put into the greylist.
GREYLIST_USER_AGENT_URLS		global	no	List of URLs, separated with spaces, containing good User-Agent to put into the greylist.
GREYLIST_URI		multisite	no	List of URI (PCRE regex), separated with spaces, to put into the greylist.
GREYLIST_URI_URLS		global	no	List of URLs, separated with spaces, containing bad URI to put into the greylist.

When using stream mode, only IP, RDNS and ASN checks will be done.

Whitelisting

STREAM support

You can use the following settings to set up whitelisting :

Setting	Default	Context	Multiple	Description
USE_WHITELIST	yes	multisite	no	Activate whitelist feature.
WHITELIST_IP	20.191.45.212 40.88.21.235 40.76.173.151 40.76.163.7 20.185.79.47 52.142.26.175 20.185.79.15 52.142.24.149 40.76.162.208 40.76.163.23 40.76.162.191 40.76.162.247 54.208.102.37 107.21.1.8	multisite	no	List of IP/network, separated with spaces, to put into the whitelist.
WHITELIST_IP_URLS		global	no	List of URLs, separated with spaces, containing good IP/network to whitelist.
WHITELIST_RDNS_GLOBAL	yes	multisite	no	Only perform RDNS whitelist checks on global IP addresses.
WHITELIST_RDNS	.google.com .googlebot.com .yandex.ru .yandex.net .yandex.com .search.msn.com .baidu.com .baidu.jp .crawl.yahoo.net .fwd.linkedin.com .twitter.com .twttr.com .discord.com	multisite	no	List of reverse DNS suffixes, separated with spaces, to whitelist.
WHITELIST_RDNS_URLS		global	no	List of URLs, separated with spaces, containing reverse DNS suffixes to whitelist.
WHITELIST_ASN	32934	multisite	no	List of ASN numbers, separated with spaces, to whitelist.
WHITELIST_ASN_URLS		global	no	List of URLs, separated with spaces, containing ASN to whitelist.
WHITELIST_USER_AGENT		multisite	no	List of User-Agent (PCRE regex), separated with spaces, to whitelist.
WHITELIST_USER_AGENT_URLS		global	no	List of URLs, separated with spaces, containing good User-Agent to whitelist.
WHITELIST_URI		multisite	no	List of URI (PCRE regex), separated with spaces, to whitelist.
WHITELIST_URI_URLS		global	no	List of URLs, separated with spaces, containing bad URI to whitelist.

When using stream mode, only IP, RDNS and ASN checks will be done.

Reverse scan

STREAM support

Reverse scan is a feature designed to detect open ports by establishing TCP connections with clients' IP addresses. Consider adding this feature if you want to detect possible open proxies or connections from servers.

We provide a list of suspicious ports by default but it can be modified to fit your needs. Be mindful, adding too many ports to the list can significantly slow down clients' connections due to the network checks. If a listed port is open, the client's access will be denied.

Please be aware, this feature is new and further improvements will be added soon.

Here is the list of settings related to reverse scan :

Setting	Default	Description
USE_REVERSE_SCAN	no	When set to yes, will enable ReverseScan.
REVERSE_SCAN_PORTS	22 80 443 3128 8000 8080	List of suspicious ports to scan.
REVERSE_SCAN_TIMEOUT	500	Specify the maximum timeout (in ms) when scanning a port.

BunkerNet

STREAM support

BunkerNet is a crowdsourced database of malicious requests shared between all BunkerWeb instances over the world.

If you enable BunkerNet, malicious requests will be sent to a remote server and will be analyzed by our systems. By doing so, we can extract malicious data from everyone's reports and give back the results to each BunkerWeb instances participating into BunkerNet.

At the moment, that feature should be considered in "beta". We only extract malicious IP and we are very strict about how we do it to avoid any "poisoning". We strongly recommend activating it (which is the default) because the more instances participate, the more data we have to improve the algorithm.

The setting used to enable or disable BunkerNet is USE_BUNKERNET (default : yes).

DNSBL

STREAM support

DNSBL or "DNS BlackList" is an external list of malicious IPs that you query using the DNS protocol. Automatic querying of that kind of blacklist is supported by BunkerWeb. If a remote DNSBL server of your choice says that the IP address of the client is in the blacklist, it will be banned.

Here is the list of settings related to DNSBL :

Setting	Default	Description
USE_DNSBL	yes	When set to yes, will enable DNSBL checking.
DNSBL_LIST	bl.blocklist.de problems.dnsbl.sorbs.net sbl.spamhaus.org xbl.spamhaus.org	List of DNSBL servers to ask.

Limiting

BunkerWeb supports applying a limit policy to :

• Number of connections per IP
• Number of requests per IP and URL within a time period

Please note that it should not be considered as an effective solution against DoS or DDoS but rather as an anti-bruteforce measure or rate limit policy for API.

In both cases (connections or requests) if the limit is reached, the client will receive the HTTP status "429 - Too Many Requests".

Connections

STREAM support

The following settings are related to the Limiting connections feature :

Setting	Default	Description
USE_LIMIT_CONN	yes	When set to yes, will limit the maximum number of concurrent connections for a given IP.
LIMIT_CONN_MAX_HTTP1	10	Maximum number of concurrent connections when using HTTP1 protocol.
LIMIT_CONN_MAX_HTTP2	100	Maximum number of concurrent streams when using HTTP2 protocol.
LIMIT_CONN_MAX_STREAM	10	Maximum number of connections per IP when using stream.

Requests

STREAM support

The following settings are related to the Limiting requests feature :

Setting	Default	Context	Multiple	Description
USE_LIMIT_REQ	yes	multisite	no	Activate limit requests feature.
LIMIT_REQ_URL	/	multisite	yes	URL (PCRE regex) where the limit request will be applied or special value / for all requests.
LIMIT_REQ_RATE	2r/s	multisite	yes	Rate to apply to the URL (s for second, m for minute, h for hour and d for day).
USE_LIMIT_CONN	yes	multisite	no	Activate limit connections feature.
LIMIT_CONN_MAX_HTTP1	10	multisite	no	Maximum number of connections per IP when using HTTP/1.X protocol.
LIMIT_CONN_MAX_HTTP2	100	multisite	no	Maximum number of streams per IP when using HTTP/2 protocol.
LIMIT_CONN_MAX_STREAM	10	multisite	no	Maximum number of connections per IP when using stream.

Please note that you can add different rates for different URLs by adding a number as a suffix to the settings for example : LIMIT_REQ_URL_1=^/url1$, LIMIT_REQ_RATE_1=5r/d, LIMIT_REQ_URL_2=^/url2/subdir/.*$, LIMIT_REQ_RATE_2=1r/m, ...

Another important thing to note is that LIMIT_REQ_URL values are PCRE regex.

Country

STREAM support

The country security feature allows you to apply policy based on the country of the IP address of clients :

• Deny any access if the country is in a blacklist
• Only allow access if the country is in a whitelist (other security checks will still be executed)

Here is the list of related settings :

Setting	Default	Context	Multiple	Description
BLACKLIST_COUNTRY		multisite	no	Deny access if the country of the client is in the list (ISO 3166-1 alpha-2 format separated with spaces).
WHITELIST_COUNTRY		multisite	no	Deny access if the country of the client is not in the list (ISO 3166-1 alpha-2 format separated with spaces).

Using both country blacklist and whitelist at the same time makes no sense. If you do, please note that only the whitelist will be executed.

Authentication

Auth basic

STREAM support

You can quickly protect sensitive resources like the admin area for example, by requiring HTTP basic authentication. Here is the list of related settings :

Setting	Default	Description
USE_AUTH_BASIC	no	When set to yes HTTP auth basic will be enabled.
AUTH_BASIC_LOCATION	sitewide	Location (URL) of the sensitive resource. Use special value sitewide to enable everywhere.
AUTH_BASIC_USER	changeme	The username required.
AUTH_BASIC_PASSWORD	changeme	The password required.
AUTH_BASIC_TEXT	Restricted area	Text to display in the auth prompt.

Auth request

You can deploy complex authentication (e.g. SSO), by using the auth request settings (see here for more information on the feature). Please note that you will find Authelia and Authentik examples in the repository.

Auth request settings are related to reverse proxy rules.

Setting	Default	Context	Multiple	Description
REVERSE_PROXY_AUTH_REQUEST		multisite	yes	Enable authentication using an external provider (value of auth_request directive).
REVERSE_PROXY_AUTH_REQUEST_SIGNIN_URL		multisite	yes	Redirect clients to sign-in URL when using REVERSE_PROXY_AUTH_REQUEST (used when auth_request call returned 401).
REVERSE_PROXY_AUTH_REQUEST_SET		multisite	yes	List of variables to set from the authentication provider, separated with ; (values of auth_request_set directives).

Monitoring and reporting

Monitoring (PRO)

The monitoring plugin lets you collect and retrieve metrics about BunkerWeb. By enabling it, your instance(s) will start collecting various data related to attacks, requests and performance. You can then retrieve them by calling the /monitoring API endpoint on regular basis or by using other plugins like the Prometheus exporter one.

List of features

• Enable collection of various BunkerWeb metrics
• Retrieve metrics from the API
• Use in combination with other plugins (e.g. Prometheus exporter)
• Dedicate UI page to monitor your instance(s)

List of settings

Setting	Default	Context	Multiple	Description
USE_MONITORING	yes	global	no	Enable monitoring of BunkerWeb.
MONITORING_METRICS_DICT_SIZE	10M	global	no	Size of the dict to store monitoring metrics.

Prometheus exporter (PRO)

The Prometheus exporter plugin adds a Prometheus exporter on your BunkerWeb instance(s). When enabled, you can configure your Prometheus instance(s) to scrape a specific endpoint on Bunkerweb and gather internal metrics.

We also provide a Grafana dashboard that you can import into your own instance and connect to your own Prometheus datasource.

Please note that the use of Prometheus exporter plugin requires to enable the Monitoring plugin (USE_MONITORING=yes)

List of features

• Prometheus exporter providing internal BunkerWeb metrics
• Dedicated and configurable port, listen IP and URL
• Whitelist IP/network for maximum security

List of settings

Setting	Default	Context	Multiple	Description
USE_PROMETHEUS_EXPORTER	no	global	no	Enable the Prometheus export.
PROMETHEUS_EXPORTER_IP	0.0.0.0	global	no	Listening IP of the Prometheus exporter.
PROMETHEUS_EXPORTER_PORT	9113	global	no	Listening port of the Prometheus exporter.
PROMETHEUS_EXPORTER_URL	/metrics	global	no	HTTP URL of the Prometheus exporter.
PROMETHEUS_EXPORTER_ALLOW_IP	127.0.0.0/8 10.0.0.0/8 172.16.0.0/12 192.168.0.0/16	global	no	List of IP/networks allowed to contact the Prometheus exporter endpoint.

Reporting (PRO)

Monitoring plugin needed

This plugins requires the Monitoring Pro plugin to be installed and enabled with the USE_MONITORING setting set to yes.

The Reporting plugin provides a comprehensive solution for regular reporting of important data from BunkerWeb, including global statistics, attacks, bans, requests, reasons, and AS information. It offers a wide range of features, including automatic report creation, customization options, and seamless integration with monitoring pro plugin. With the Reporting plugin, you can easily generate and manage reports to monitor the performance and security of your application.

List of features

• Regular reporting of important data from BunkerWeb, including global statistics, attacks, bans, requests, reasons, and AS information.
• Integration with Monitoring Pro plugin for seamless integration and enhanced reporting capabilities.
• Support for webhooks (classic, Discord, and Slack) for real-time notifications.
• Support for SMTP for email notifications.
• Configuration options for customization and flexibility.

List of settings

Setting	Default	Context	Description
USE_REPORTING_SMTP	no	global	Enable sending the report via email.
USE_REPORTING_WEBHOOK	no	global	Enable sending the report via webhook.
REPORTING_SCHEDULE	weekly	global	The frequency at which reports are sent.
REPORTING_WEBHOOK_URLS		global	List of webhook URLs to receive the report in Markdown (separated by spaces).
REPORTING_SMTP_EMAILS		global	List of email addresses to receive the report in HTML format (separated by spaces).
REPORTING_SMTP_HOST		global	The host server used for SMTP sending.
REPORTING_SMTP_PORT	465	global	The port used for SMTP. Please note that there are different standards depending on the type of connection (SSL = 465, TLS = 587).
REPORTING_SMTP_FROM_EMAIL		global	The email address used as the sender. Note that 2FA must be disabled for this email address.
REPORTING_SMTP_FROM_USER		global	The user authentication value for sending via the from email address.
REPORTING_SMTP_FROM_PASSWORD		global	The password authentication value for sending via the from email address.
REPORTING_SMTP_SSL	SSL	global	Determine whether or not to use a secure connection for SMTP.

Information and behavior

• case USE_REPORTING_SMTP is set to yes, the setting REPORTING_SMTP_EMAILS must be set.
• case USE_REPORTING_WEBHOOK is set to yes, the setting REPORTING_WEBHOOK_URLS must be set.
• Accepted values for REPORTING_SCHEDULE are daily, weeklyand monthly.
• case no REPORTING_SMTP_FROM_USER and REPORTING_SMTP_FROM_PASSWORD are set, the plugin will try to send the email without authentication.
• case REPORTING_SMTP_FROM_USER isn't set but REPORTING_SMTP_FROM_PASSWORD is set, the plugin will use the REPORTING_SMTP_FROM_EMAIL as the username.
• case the job fails, the plugin will retry sending the report in the next execution.