Bug 1598831 (CVE-2018-10896) - CVE-2018-10896 cloud-init: default configuration disabled deletion of SSH host keys
Summary: CVE-2018-10896 cloud-init: default configuration disabled deletion of SSH hos...
Status: NEW
Alias: CVE-2018-10896
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
Target Milestone: ---
Assignee: Red Hat Product Security
QA Contact:
Depends On: 1574338 1598834 1598832 1598833
Blocks: 1576571
TreeView+ depends on / blocked
Reported: 2018-07-06 15:04 UTC by Laura Pardo
Modified: 2019-09-29 14:43 UTC (History)
10 users (show)

Fixed In Version:
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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.
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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.


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:


Comment 7 Doran Moppert 2018-08-07 00:59:01 UTC
Upstream commit now merged to master:


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