Merge pull request #2226 from mbologna/nginx-forbidden

Feat: ban nginx forbidden accesses

ChangeLog

@@ -19,6 +19,7 @@ ver. 1.0.3-dev-1 (20??/??/??) - development nightly edition
   (value read from `/proc/sys/net/ipv6/conf/all/disable_ipv6`) if available, otherwise seeks over local IPv6 from network interfaces
   if available for platform and uses DNS to find local IPv6 as a fallback only
 * improve `ignoreself` by considering all local addresses from network interfaces additionally to IPs from hostnames (gh-3132)
+* `filter.d/nginx-forbidden.conf` - new filter to ban forbidden locations, e. g. using `deny` directive (gh-2226)
 
 
 ver. 1.0.2 (2022/11/09) - finally-war-game-test-tape-not-a-nuclear-alarm

config/filter.d/nginx-forbidden.conf

@@ -0,0 +1,25 @@
+# fail2ban filter configuration for nginx forbidden accesses
+#
+# If you have configured nginx to forbid some paths in your webserver, e.g.:
+#
+#       location ~ /\. {
+#         deny all;
+#       }
+#
+# if a client tries to access https://yoursite/.user.ini then you will see
+# in nginx error log:
+#
+# 2018/09/14 19:03:05 [error] 2035#2035: *9134 access forbidden by rule, client: 10.20.30.40, server: www.example.net, request: "GET /.user.ini HTTP/1.1", host: "www.example.net", referrer: "https://www.example.net"
+#
+# By carefully setting this filter we ban every IP that tries too many times to
+# access forbidden resources.
+#
+# Author: Michele Bologna https://www.michelebologna.net/
+
+[Definition]
+failregex = \[error\] \d+#\d+: \*\d+ access forbidden by rule, client: <HOST>
+ignoreregex =
+
+datepattern = {^LN-BEG}
+
+journalmatch = _SYSTEMD_UNIT=nginx.service + _COMM=nginx

config/jail.conf

@@ -395,6 +395,10 @@ logpath  = %(nginx_error_log)s
 port    = http,https
 logpath = %(nginx_access_log)s
 
+[nginx-forbidden]
+port     = http,https
+logpath  = %(nginx_error_log)s
+
 # Ban attackers that try to use PHP's URL-fopen() functionality
 # through GET/POST variables. - Experimental, with more than a year
 # of usage in production environments.

fail2ban/tests/files/logs/nginx-forbidden

@@ -0,0 +1,5 @@
+# failJSON: { "time": "2018-09-14T19:03:05", "match": true , "host": "12.34.56.78" }
+2018/09/14 19:03:05 [error] 2035#2035: *9134 access forbidden by rule, client: 12.34.56.78, server: www.example.net, request: "GET /wp-content/themes/evolve/js/back-end/libraries/fileuploader/upload_handler.php HTTP/1.1", host: "www.example.net", referrer: "http://example.net/foo.php"
+
+# failJSON: { "time": "2018-09-13T15:42:05", "match": true , "host": "12.34.56.78" }
+2018/09/13 15:42:05 [error] 2035#2035: *287 access forbidden by rule, client: 12.34.56.78, server: www.example.com, request: "GET /wp-config.php~ HTTP/1.1", host: "www.example.com"