From bd432fed920d0587c1ef9a7227a7157db86990fa Mon Sep 17 00:00:00 2001
From: Toni de la Fuente <toni@blyx.com>
Date: Tue, 7 Apr 2020 16:46:46 +0200
Subject: [PATCH] New check for Metadata Service Version 2 #413

---
 checks/check_extra786 | 52 +++++++++++++++++++++++++++++++++++++++++++
 groups/group7_extras  |  2 +-
 2 files changed, 53 insertions(+), 1 deletion(-)
 create mode 100644 checks/check_extra786

diff --git a/checks/check_extra786 b/checks/check_extra786
new file mode 100644
index 00000000..f7093bcf
--- /dev/null
+++ b/checks/check_extra786
@@ -0,0 +1,52 @@
+#!/usr/bin/env bash
+
+# Prowler - the handy cloud security tool (copyright 2020) by Toni de la Fuente
+#
+# Licensed under the Apache License, Version 2.0 (the "License"); you may not
+# use this file except in compliance with the License. You may obtain a copy
+# of the License at http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software distributed
+# under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR
+# CONDITIONS OF ANY KIND, either express or implied. See the License for the
+# specific language governing permissions and limitations under the License.
+CHECK_ID_extra786="7.86"
+CHECK_TITLE_extra786="[extra786] Check if EC2 Instance Metadata Service Version 2 (IMDSv2) is Enabled and Required (Not Scored) (Not part of CIS benchmark)"
+CHECK_SCORED_extra786="NOT_SCORED"
+CHECK_TYPE_extra786="EXTRA"
+CHECK_ALTERNATE_check770="extra786"
+
+extra786(){
+  for regx in $REGIONS; do 
+    TEMP_EXTRA786_FILE=$(mktemp -t prowler-${ACCOUNT_NUM}-es-domain.EXTRA779.XXXXXXXXXX)
+    $AWSCLI ec2 describe-instances $PROFILE_OPT --region $regx \
+      --query 'Reservations[*].Instances[*].{HttpTokens:MetadataOptions.HttpTokens,HttpEndpoint:MetadataOptions.HttpEndpoint,InstanceId:InstanceId}' \
+      --output text --max-items $MAXITEMS > $TEMP_EXTRA786_FILE
+    # if the file contains data, there are instances in that region 
+    if [[ -s "$TEMP_EXTRA786_FILE" ]];then
+      # here we read content from the file fields instanceid httptokens_status httpendpoint
+      while read httpendpoint httptokens_status instanceid  ; do 
+        #echo i:$instanceid tok:$httptokens_status end:$httpendpoint
+        if [[ "$httpendpoint" == "enabled" &&  "$httptokens_status" == "required" ]];then
+          textPass "$regx: EC2 Instance $instanceid has IMDSv2 enabled and required" "$regx"
+        elif [[ "$httpendpoint" == "disabled" ]];then 
+          textInfo "$regx: EC2 Instance $instanceid has HTTP endpoint access to metadata service disabled" "$regx"
+        else
+          textFail "$regx: EC2 Instance $instanceid has IMDSv2 disabled or not required" "$regx"
+        fi 
+      done < <(cat $TEMP_EXTRA786_FILE)
+    else 
+     textInfo "$regx: no EC2 Instances found" "$regx"
+    fi 
+    rm -fr $TEMP_EXTRA786_FILE
+  done
+}
+
+# Remediation:
+
+# aws ec2 modify-instance-metadata-options \
+#     --instance-id i-1234567898abcdef0 \
+#     --http-tokens required \
+#     --http-endpoint enabled
+
+# More information here https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/configuring-instance-metadata-service.html
diff --git a/groups/group7_extras b/groups/group7_extras
index bbb27d31..57062cb7 100644
--- a/groups/group7_extras
+++ b/groups/group7_extras
@@ -15,7 +15,7 @@ GROUP_ID[7]='extras'
 GROUP_NUMBER[7]='7.0'
 GROUP_TITLE[7]='Extras - all non CIS specific checks - [extras] ****************'
 GROUP_RUN_BY_DEFAULT[7]='Y' # run it when execute_all is called
-GROUP_CHECKS[7]='extra71,extra72,extra73,extra74,extra75,extra76,extra77,extra78,extra79,extra710,extra711,extra712,extra713,extra714,extra715,extra716,extra717,extra718,extra719,extra720,extra721,extra722,extra723,extra724,extra725,extra726,extra727,extra728,extra729,extra730,extra731,extra732,extra733,extra734,extra735,extra736,extra737,extra738,extra739,extra740,extra741,extra742,extra743,extra744,extra745,extra746,extra747,extra748,extra749,extra750,extra751,extra752,extra753,extra754,extra755,extra756,extra757,extra758,extra761,extra762,extra763,extra764,extra765,extra767,extra768,extra769,extra770,extra771,extra772,extra773,extra774,extra775,extra776,extra777,extra778,extra779,extra780,extra781,extra782,extra783,extra784,extra785'
+GROUP_CHECKS[7]='extra71,extra72,extra73,extra74,extra75,extra76,extra77,extra78,extra79,extra710,extra711,extra712,extra713,extra714,extra715,extra716,extra717,extra718,extra719,extra720,extra721,extra722,extra723,extra724,extra725,extra726,extra727,extra728,extra729,extra730,extra731,extra732,extra733,extra734,extra735,extra736,extra737,extra738,extra739,extra740,extra741,extra742,extra743,extra744,extra745,extra746,extra747,extra748,extra749,extra750,extra751,extra752,extra753,extra754,extra755,extra756,extra757,extra758,extra761,extra762,extra763,extra764,extra765,extra767,extra768,extra769,extra770,extra771,extra772,extra773,extra774,extra775,extra776,extra777,extra778,extra779,extra780,extra781,extra782,extra783,extra784,extra785,extra786'
 
 # Extras 759 and 760 (lambda variables and code secrets finder are not included)
 # to run detect-secrets use `./prowler -g secrets`