Attacker Value
Moderate
0

CVE-2020-3158

Disclosure Date: February 20, 2020

Exploitability

(2 users assessed) High
Attack Vector
Network
Privileges Required
None
User Interaction
None

Description

A vulnerability in the High Availability (HA) service of Cisco Smart Software Manager On-Prem could allow an unauthenticated, remote attacker to access a sensitive part of the system with a high-privileged account. The vulnerability is due to a system account that has a default and static password and is not under the control of the system administrator. An attacker could exploit this vulnerability by using this default account to connect to the affected system. A successful exploit could allow the attacker to obtain read and write access to system data, including the configuration of an affected device. The attacker would gain access to a sensitive portion of the system, but the attacker would not have full administrative rights to control the device.

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3
Ratings
  • Attacker Value
    Medium
  • Exploitability
    Medium
Technical Analysis

It looks like the base software is installed as part of a Centos 7 system. Customizations are found in the ‘hardening’ directory on the installer ISO file.

atlantis-post-install.sh looks interesting, as it sets up all of the services and unpacks the custom file satellite-install.tgz

Hasty diff between 201910 and 202001

$ diff -u /mnt/hardening/atlantis-post-install.sh atlantis-post-install.sh 
--- /mnt/hardening/atlantis-post-install.sh	2019-11-20 13:01:24.000000000 -0600
+++ atlantis-post-install.sh	2020-01-29 22:03:41.000000000 -0600
@@ -68,7 +68,8 @@
 firewall-offline-cmd --zone=user --add-service=ssh
 firewall-offline-cmd --zone=user --add-rich-rule='rule family=ipv4 port port=443 protocol=tcp reject'
 firewall-offline-cmd --zone=user --add-rich-rule='rule family=ipv6 port port=443 protocol=tcp reject'
-# dmz zone already exists
+# dmz zone already exists (ssh service is inherited - we remopve it here)
+firewall-offline-cmd --zone=dmz --remove-service-from-zone=ssh
 firewall-offline-cmd --zone=dmz --add-rich-rule='rule family=ipv4 port port=80 protocol=tcp reject'
 firewall-offline-cmd --zone=dmz --add-rich-rule='rule family=ipv4 port port=443 protocol=tcp reject'
 firewall-offline-cmd --zone=dmz --add-rich-rule='rule family=ipv4 port port=8443 protocol=tcp reject'

Interestingly the docker layers that appear to be part of the build leak a number of internal Cisco resource names:

    curl http://timaeus.cisco.com/devKey \u003e ~/.ssh/id_rsa \u0026\u0026     chmod 0600 ~/.ssh/id_rsa \u0026\u0026     eval `ssh-agent` \u0026\u0026     ssh-add \u0026\u0026     ssh-keyscan -p 7999 -t rsa bitbucket-eng-sjc1.cisco.com \u003e\u003e ~/.ssh/known_hosts \u0026\u0026     bundle install --with cerberus --without development test alpha \u0026\u0026     rm -rf ~/.ssh \u0026\u0026     bundle config --global frozen 1;"},{"created":"2019-11-21T05:24:36.571974064Z","created_by":"|0 /bin/sh -c sed -i '/jessie-updates main/d' /etc/apt/sources.list"},{"created":"2019-11-21T05:26:54.698408023Z","created_by":"|0 /bin/sh -c apt-get update \u0026\u0026 apt-get install -y postgresql-client"},{"created":"2019-11-21T05:26:55.987328112Z","created_by":"|0 /bin/sh -c ln -sf /dev/stdout /usr/src/log/sidekiq.log"},{"created":"2019-11-21T05:26:56.230921929Z","created_by":"/bin/sh -c #(nop) COPY file:31a545d2f5f434f3e031ea7c4fd4af19d67f5fb40e217c1ed1ef665da663abce in /usr/local/bin/ "},{"created":"2019-11-21T05:26:56.391769508Z","created_by":"/bin/sh -c #(nop)  CMD [\"/bin/sh\" \"-c\" \"/bin/bash /usr/local/bin/startup.sh\"]","empty_layer":true}],"os":"linux","rootfs":{"type":"layers","diff_ids":[

Other internal creds seem to be baked into the app as well, even in the current version. This app looks worthy of future explorations, especially for the other secrets it contains. I’m just not sure how much install footprint it has in the real world, at least I’ve never worked for a company that would be the target market for this app.

2
Ratings
  • Attacker Value
    Medium
  • Exploitability
    Very High
Technical Analysis

This vulnerability only exists if the High Availability (HA) service of Cisco Smart Software Manager On-Prem is enabled, which is not by default. This service enables an attacker to authenticate using a high-privilege default account with a static password (hardcoded). This attack could be executed by anyone without any specific skills, all he has to do is to authenticate using the default password, and no valid login is even required.

This looks like a critical vulnerability, since you can have access (read and write) to the system’s data and change configurations. However, it looks like the level of privileges would not grant access to the sensitive parts of the system. So, that said, and considering the affected service is not enabled by default, it does not look that critical.

This requires more investigation to understand what can be done with this level of privileges. I did a very quick search on the internet and was not able to find this default password. Some patch reversing might need to be done to find it and start investigating.

General Information

Additional Info

Technical Analysis