Bug 1598831 (CVE-2018-10896)

Summary:	CVE-2018-10896 cloud-init: default configuration disabled deletion of SSH host keys
Product:	[Other] Security Response	Reporter:	Laura Pardo <lpardo>
Component:	vulnerability	Assignee:	Red Hat Product Security <security-response-team>
Status:	CLOSED ERRATA	QA Contact:
Severity:	low	Docs Contact:
Priority:	low
Version:	unspecified	CC:	adimania, apevec, dmoppert, gholms, jgreguske, lars, rmccabe, shardy, s, virt-maint
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	If docs needed, set a value
Doc Text:	The default cloud-init configuration included "ssh_deletekeys: 0", disabling cloud-init's deletion of ssh host keys. In some environments, this could lead to instances created by cloning a golden master or template system, sharing ssh host keys, and being able to impersonate one another or conduct man-in-the-middle attacks.	Story Points:	---
Clone Of:		Environment:
Last Closed:	2020-07-21 19:27:38 UTC	Type:	---
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:
Bug Depends On:	1574338, 1598832, 1598833, 1598834, 1814152, 1826218, 1855595
Bug Blocks:	1576571

Description Laura Pardo 2018-07-06 15:04:16 UTC

A flaw was found in cloud-init. SSH host keys are not regenerated when new VM instances are created in combination with hashicorp packer and cloud-init. This could lead to the Man In The Middle (MITM) attack.


References:
https://bugzilla.redhat.com/show_bug.cgi?id=1574338

Comment 1 Laura Pardo 2018-07-06 15:05:49 UTC

Created cloud-init tracking bugs for this issue:

Affects: epel-6 [bug 1598833]
Affects: fedora-all [bug 1598832]

Comment 5 Doran Moppert 2018-07-11 00:32:13 UTC

Reported upstream:

https://bugs.launchpad.net/cloud-init/+bug/1781094

Comment 7 Doran Moppert 2018-08-07 00:59:01 UTC

Upstream commit now merged to master:

https://git.launchpad.net/cloud-init/commit/?id=e218c597

Comment 8 errata-xmlrpc 2020-07-21 15:30:41 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8

Via RHSA-2020:3050 https://access.redhat.com/errata/RHSA-2020:3050

Comment 9 Product Security DevOps Team 2020-07-21 19:27:38 UTC

This bug is now closed. Further updates for individual products will be reflected on the CVE page(s):

https://access.redhat.com/security/cve/cve-2018-10896

Comment 11 errata-xmlrpc 2020-09-08 07:56:18 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8.2 Extended Update Support

Via RHSA-2020:3644 https://access.redhat.com/errata/RHSA-2020:3644

Comment 12 errata-xmlrpc 2020-09-29 19:40:41 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 7

Via RHSA-2020:3898 https://access.redhat.com/errata/RHSA-2020:3898