Merge pull request #818 from slowriot/master

adding filter to detect Shellshock attack attempts with Apache

ChangeLog

@@ -57,6 +57,7 @@ ver. 0.9.1 (2014/xx/xx) - better, faster, stronger
    - New filters:
      - monit  Thanks Jason H Martin
      - directadmin  Thanks niorg
+     - apache-shellshock  Thanks Eugene Hopkinson (SlowRiot)
    - New actions:
      - symbiosis-blacklist-allports  for Bytemark symbiosis firewall
    - fail2ban-client can fetch the running server version

THANKS

@@ -34,6 +34,7 @@ David Nutter
 Derek Atkins
 Eric Gerbier
 Enrico Labedzki
+Eugene Hopkinson (SlowRiot)
 ftoppi
 François Boulogne
 Frédéric

config/filter.d/apache-shellshock.conf

@@ -0,0 +1,26 @@
+# Fail2Ban filter to block web requests containing custom headers attempting to exploit the shellshock bug
+#
+#
+
+[INCLUDES]
+
+# overwrite with apache-common.local if _apache_error_client is incorrect.
+before = apache-common.conf
+
+[Definition]
+
+failregex = ^%(_apache_error_client)s (AH01215: )?/bin/(ba)?sh: warning: HTTP_.*?: ignoring function definition attempt(, referer: \S+)?\s*$
+            ^%(_apache_error_client)s (AH01215: )?/bin/(ba)?sh: error importing function definition for `HTTP_.*?'(, referer: \S+)?\s*$
+
+ignoreregex = 
+
+
+# DEV Notes:
+#
+# https://wiki.apache.org/httpd/ListOfErrors for apache error IDs
+#
+# example log lines: 
+# [Thu Sep 25 09:27:18.813902 2014] [cgi:error] [pid 16860] [client 89.207.132.76:59635] AH01215: /bin/bash: warning: HTTP_TEST: ignoring function definition attempt
+# [Thu Sep 25 09:29:56.141832 2014] [cgi:error] [pid 16864] [client 162.247.73.206:41273] AH01215: /bin/bash: error importing function definition for `HTTP_TEST'
+#
+# Author: Eugene Hopkinson (riot@riot.so)

config/jail.conf

@@ -283,6 +283,11 @@ port     = http,https
 logpath  = %(apache_error_log)s
 maxretry = 2
 
+[apache-shellshock]
+
+port    = http,https
+logpath = $(apache_error_log)s
+maxretry = 1
 
 [nginx-http-auth]
 

fail2ban/tests/files/logs/apache-shellshock

@@ -0,0 +1,4 @@
+# failJSON: { "time": "2014-09-25T09:27:18", "match": true , "host": "89.207.132.76" }
+[Thu Sep 25 09:27:18.813902 2014] [cgi:error] [pid 16860] [client 89.207.132.76:59635] AH01215: /bin/bash: warning: HTTP_TEST: ignoring function definition attempt
+# failJSON: { "time": "2014-09-25T09:29:56", "match": true , "host": "162.247.73.206" }
+[Thu Sep 25 09:29:56.141832 2014] [cgi:error] [pid 16864] [client 162.247.73.206:41273] AH01215: /bin/bash: error importing function definition for `HTTP_TEST'