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-3-2-2.yml b/metadata/service/system/cis/cis-3-2-2.yml
new file mode 100644
index 0000000..eb992b8
--- /dev/null
+++ b/metadata/service/system/cis/cis-3-2-2.yml
@@ -0,0 +1,48 @@
+# 3.2.2 Ensure ICMP redirects are not accepted
+#
+# Description
+# ===========
+# ICMP redirect messages are packets that convey routing information and tell
+# your host (acting as a router) to send packets via an alternate path. It is
+# a way of allowing an outside routing device to update your system routing
+# tables. By setting net.ipv4.conf.all.accept_redirects to 0, the system will
+# not accept any ICMP redirect messages, and therefore, won't allow outsiders
+# to update the system's routing tables.
+#
+# Rationale
+# =========
+# Attackers could use bogus ICMP redirect messages to maliciously alter the
+# system routing tables and get them to send packets to incorrect networks and
+# allow your system packets to be captured.
+#
+# Audit
+# =====
+#
+# Run the following commands and verify output matches:
+#
+#   # sysctl net.ipv4.conf.all.accept_redirects
+#   net.ipv4.conf.all.accept_redirects = 0
+#   # sysctl net.ipv4.conf.default.accept_redirects
+#   net.ipv4.conf.default.accept_redirects = 0
+#
+# Remediation
+# ===========
+#
+# Set the following parameters in the /etc/sysctl.conf file:
+#
+#   net.ipv4.conf.all.accept_redirects = 0
+#   net.ipv4.conf.default.accept_redirects = 0
+#
+# Run the following commands to set the active kernel parameters:
+#
+#   # sysctl -w net.ipv4.conf.all.accept_redirects=0
+#   # sysctl -w net.ipv4.conf.default.accept_redirects=0
+#   # sysctl -w net.ipv4.route.flush=1
+
+parameters:
+  linux:
+    system:
+      kernel:
+        sysctl:
+          net.ipv4.conf.all.accept_redirects: 0
+          net.ipv4.conf.default.accept_redirects: 0