CIS compliance (sysctl, limits)
* CIS 1.5.1 Ensure core dumps are restricted
* CIS 1.5.3 Ensure address space layout randomization (ASLR) is enabled
* CIS 3.1.2 Ensure packet redirect sending is disabled
* CIS 3.2.1 Ensure source routed packets are not accepted
* CIS 3.2.2 Ensure ICMP redirects are not accepted
* CIS 3.2.3 Ensure secure ICMP redirects are not accepted
* CIS 3.2.4 Ensure suspicious packets are logged
* CIS 3.2.5 Ensure broadcast ICMP requests are ignored
* CIS 3.2.6 Ensure bogus ICMP responses are ignored
* CIS 3.2.7 Ensure Reverse Path Filtering is enabled
* CIS 3.2.8 Ensure TCP SYN Cookies is enabled
All sysctls are valid for Ubuntu 14.04, Ubuntu 16.04.
Change-Id: I48f34c55d97a78c253d4810db46b2a04ff5c0c1a
diff --git a/metadata/service/system/cis/cis-3-2-6.yml b/metadata/service/system/cis/cis-3-2-6.yml
new file mode 100644
index 0000000..5f31b07
--- /dev/null
+++ b/metadata/service/system/cis/cis-3-2-6.yml
@@ -0,0 +1,39 @@
+# 3.2.6 Ensure bogus ICMP responses are ignored
+#
+# Description
+# ===========
+# Setting icmp_ignore_bogus_error_responses to 1 prevents the kernel from
+# logging bogus responses (RFC-1122 non-compliant) from broadcast reframes,
+# keeping file systems from filling up with useless log messages.
+#
+# Rationale
+# =========
+# Some routers (and some attackers) will send responses that violate RFC-1122
+# and attempt to fill up a log file system with many useless error messages.
+#
+# Audit
+# =====
+#
+# Run the following commands and verify output matches:
+#
+# # sysctl net.ipv4.icmp_ignore_bogus_error_responses
+# net.ipv4.icmp_ignore_bogus_error_responses = 1
+#
+# Remediation
+# ===========
+#
+# Set the following parameter in the /etc/sysctl.conf file:
+#
+# net.ipv4.icmp_ignore_bogus_error_responses = 1
+#
+# Run the following commands to set the active kernel parameters:
+#
+# # sysctl -w net.ipv4.icmp_ignore_bogus_error_responses=1
+# # sysctl -w net.ipv4.route.flush=1
+
+parameters:
+ linux:
+ system:
+ kernel:
+ sysctl:
+ net.ipv4.icmp_ignore_bogus_error_responses: 1