Bug 1557822 (CVE-2018-1085) - CVE-2018-1085 openshift-ansible: Incorrectly quoted values in etcd.conf causes disabling of SSL client certificate authentication
Summary: CVE-2018-1085 openshift-ansible: Incorrectly quoted values in etcd.conf cause...
Keywords:
Status: CLOSED ERRATA
Alias: CVE-2018-1085
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
high
high
Target Milestone: ---
Assignee: Red Hat Product Security
QA Contact:
URL:
Whiteboard:
: 1557821 (view as bug list)
Depends On: 1557895 1557897 1574266
Blocks: 1557824
TreeView+ depends on / blocked
 
Reported: 2018-03-19 01:45 UTC by Sam Fowler
Modified: 2019-09-29 14:35 UTC (History)
12 users (show)

Fixed In Version: openshift-ansible 3.9.23-1, openshift-ansible 3.7.46-1
Doc Type: If docs needed, set a value
Doc Text:
OpenShift and Atomic Enterprise Ansible deploys a misconfigured etcd file that causes the SSL client certificate authentication to be disabled. Quotations around the values of ETCD_CLIENT_CERT_AUTH and ETCD_PEER_CLIENT_CERT_AUTH in etcd.conf result in etcd being configured to allow remote users to connect without any authentication if they can access the etcd server bound to the network on the master nodes. An attacker could use this flaw to read and modify all the data about the Openshift cluster in the etcd datastore, potentially adding another compute node, or bringing down the entire cluster.
Clone Of:
Environment:
Last Closed: 2019-06-10 10:17:58 UTC


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System ID Priority Status Summary Last Updated
Red Hat Product Errata RHSA-2018:2013 None None None 2018-06-27 18:01:23 UTC

Description Sam Fowler 2018-03-19 01:45:14 UTC
OpenShift and Atomic Enterprise Ansible deploys a misconfigured etcd file that causes SSL client certificate authentication to be disabled. Quotations around the values of ETCD_CLIENT_CERT_AUTH and ETCD_PEER_CLIENT_CERT_AUTH in etcd.conf result in etcd being configured to allow remote users to connect without any authentication.

Comment 1 Sam Fowler 2018-03-19 01:45:20 UTC
Acknowledgments:

Name: David Hocky (Comcast)

Comment 5 Sam Fowler 2018-03-19 23:30:38 UTC
*** Bug 1557821 has been marked as a duplicate of this bug. ***

Comment 13 Jason Shepherd 2018-03-23 02:59:16 UTC
Statement:

This issue affects Openshift Container Platform (OCP) only if you use the container installation method. The container installation method is tech preview in 3.7.1. This issue affected all users who did a containerized etcd in OCP versions 3.7.1-3.6.

If etcd is installed via RPM and run via '/usr/bin/etcd' it's not affected by this flaw. You can check if etcd is being run from '/usr//bin/etcd' using a 'ps' command such as this on the master nodes. If Installed via RPM you should get output similar to:

ps -ef | grep etcd
$/usr/bin/etcd --name=master-0.example.com --data-dir=/var/lib/etcd/ --listen-client-urls=https://10.0.1.1:2379

If etcd is installed via the container method running 'docker ps' on the master will show a container running the registry.access.redhat.com/rhel7/etcd image, eg:

sudo docker ps --filter name=etcd_container
$704effa9b0cc        registry.access.redhat.com/rhel7/etcd   "/usr/bin/etcd"     56 minutes ago      Up 56 minutes                           etcd_container

Comment 14 Jason Shepherd 2018-03-26 05:39:18 UTC
Mitigation:

On master nodes where etcd has been installed using the container method:

0. Verify you can connect to etcd without providing TLS authentication credentials. On any master node, check the ETCD_LISTEN_CLIENT_URLS in /etc/etcd/etcd.conf, and use one of the client urls to connect without providing a certificate, eg:
   curl -4 curl https://10.0.1.1:2379/version -k

0a. If vulnerable output will show something like this:
   {"etcdserver":"3.2.15","etcdcluster":"3.2.0"}

0b. If not affected the connection will fail with:
    curl: (58) NSS: client certificate not found (nickname not specified)

1. update /etc/etcd/etcd.conf on the master nodes to remove quotes from these fields:
   ETCD_PEER_CLIENT_CERT_AUTH="true"
   ETCD_CLIENT_CERT_AUTH="true"
eg.
   ETCD_PEER_CLIENT_CERT_AUTH=true
   ETCD_CLIENT_CERT_AUTH=true

2. Restart the etcd container service:
   sudo systemctl restart etcd_container

3. Test if client authentication is now required using the steps from 0. above.

Comment 17 errata-xmlrpc 2018-06-27 18:01:17 UTC
This issue has been addressed in the following products:

  Red Hat OpenShift Container Platform 3.9

Via RHSA-2018:2013 https://access.redhat.com/errata/RHSA-2018:2013


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