Bug 1331465 – CVE-2016-1551 ntp: ntpd reference clock impersonation

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Bug 1331465 - (CVE-2016-1551) CVE-2016-1551 ntp: ntpd reference clock impersonation

Summary:	CVE-2016-1551 ntp: ntpd reference clock impersonation

Status:	CLOSED NOTABUG

Aliases:	CVE-2016-1551

Product:	Security Response
Classification:	Other
Component:	vulnerability (Show other bugs)
Sub Component:
Version:	unspecified
Hardware:	All Linux

Priority	low Severity low
Target Milestone:	---
Target Release:	---
Assigned To:	Red Hat Product Security
QA Contact:
Docs Contact:

URL:
Whiteboard:	impact=low,public=20160426,reported=2...
Keywords:	Security

Depends On:
Blocks:	1331437
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Reported:	2016-04-28 10:52 EDT by Martin Prpič
Modified:	2016-05-06 11:32 EDT (History)
CC List:	2 users (show)

See Also:
Fixed In Version:	ntp 4.2.8p7
Doc Type:	Bug Fix
Doc Text:
Story Points:	---
Clone Of:
Environment:
Last Closed:	2016-05-02 07:55:55 EDT
Type:	---
Regression:	---
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Documentation:	---
CRM:
Verified Versions:
Category:	---
oVirt Team:	---
RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---

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Description Martin Prpič 2016-04-28 10:52:27 EDT

The following flaw was found in ntpd:

While the majority OSes implement martian packet filtering in their network stack, at least regarding 127.0.0.0/8, a rare few will allow packets claiming to be from 127.0.0.0/8 that arrive over physical network. On these OSes, if ntpd is configured to use a reference clock an attacker can inject packets over the network that look like they are coming from that reference clock.

Upstream bugs:

http://support.ntp.org/bin/view/Main/NtpBug3020

External References:

http://support.ntp.org/bin/view/Main/SecurityNotice#April_2016_NTP_4_2_8p7_Security
http://www.talosintel.com/reports/TALOS-2016-0132/

Comment 1 Martin Prpič 2016-05-02 07:55:55 EDT

Statement:

This issue did not affect the versions of ntp as shipped with Red Hat Enterprise Linux 5, 6, and 7 as the Linux kernel drops packets from 127.0.0.0/8, mitigating this issue.

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