Bug 1331463 (CVE-2016-1549)

Summary:	CVE-2016-1549 ntp: ephemeral association time spoofing
Product:	[Other] Security Response	Reporter:	Martin Prpič <mprpic>
Component:	vulnerability	Assignee:	Red Hat Product Security <security-response-team>
Status:	CLOSED WONTFIX	QA Contact:
Severity:	low	Docs Contact:
Priority:	low
Version:	unspecified	CC:	apmukher, jaeshin, mdshaikh, mlichvar, sardella, slawomir, sshaurya, yozone
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:	ntp 4.2.8p7	Doc Type:	Bug Fix
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2016-05-30 13:39:23 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:	1332160
Bug Blocks:	1331437

Description Martin Prpič 2016-04-28 14:51:41 UTC

The following flaw was found in ntpd:

ntpd can be vulnerable to Sybil attacks. If a system is set up to use a trustedkey and if one is not using the feature introduced in ntp-4.2.8p6 allowing an optional 4th field in the ntp.keys file to specify which IPs can serve time, a malicious authenticated peer -- i.e. one where the attacker knows the private symmetric key -- can create arbitrarily-many ephemeral associations in order to win the clock selection of ntpd and modify a victim's clock.

Upstream bugs:

http://support.ntp.org/bin/view/Main/NtpBug3012

External References:

http://support.ntp.org/bin/view/Main/SecurityNotice#April_2016_NTP_4_2_8p7_Security
http://www.talosintel.com/reports/TALOS-2016-0083/

Comment 1 Martin Prpič 2016-05-02 11:37:36 UTC

Created ntp tracking bugs for this issue:

Affects: fedora-all [bug 1332160]

Comment 3 Martin Prpič 2016-06-03 14:35:23 UTC

Statement:

Red Hat Product Security has rated this issue as having Low security impact: to exploit this issue, an attacker must have access to a trustedkey if one is configured in the /etc/ntp.key file. This issue is not currently planned to be addressed in future updates. For additional information, refer to the Issue Severity Classification: https://access.redhat.com/security/updates/classification/.

Mitigation:

Assure only trusted hosts have access to the trustedkey.