Bug 1300271 - (CVE-2015-7979) CVE-2015-7979 ntp: off-path denial of service on authenticated broadcast mode
CVE-2015-7979 ntp: off-path denial of service on authenticated broadcast mode
Status: CLOSED ERRATA
Product: Security Response
Classification: Other
Component: vulnerability (Show other bugs)
unspecified
All Linux
medium Severity medium
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Assigned To: Red Hat Product Security
impact=moderate,public=20160120,repor...
: Reopened, Security
Depends On: 1300277 1317795 1332478 1332479 1332480 1356965
Blocks: 1297474 1323912
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Reported: 2016-01-20 06:43 EST by Martin Prpič
Modified: 2016-11-06 00:14 EDT (History)
3 users (show)

See Also:
Fixed In Version: ntp 4.2.8p6
Doc Type: Bug Fix
Doc Text:
It was found that when NTP was configured in broadcast mode, a remote attacker could broadcast packets with bad authentication to all clients. The clients, upon receiving the malformed packets, would break the association with the broadcast server, causing them to become out of sync over a longer period of time.
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Environment:
Last Closed: 2016-05-31 04:23:22 EDT
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CRM:
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oVirt Team: ---
RHEL 7.3 requirements from Atomic Host:
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Description Martin Prpič 2016-01-20 06:43:24 EST
It was found that when NTP is configured in broadcast mode, an off-path attacker could broadcast packets with bad authentication (wrong key, mismatched key, incorrect MAC, etc) to all clients. The clients, upon receiving the malformed packets, would break the association with the broadcast server. This could cause the time on affected clients to become out of sync over a longer period of time.

Upstream patch:

https://github.com/ntp-project/ntp/commit/fe46889f7baa75fc8e6c0fcde87706d396ce1461
Comment 2 Martin Prpič 2016-01-20 07:02:06 EST
Created ntp tracking bugs for this issue:

Affects: fedora-all [bug 1300277]
Comment 3 Martin Prpič 2016-01-21 10:25:35 EST
Mitigation:

Do not use NTP's broadcast mode by not configuring the "broadcast" directive in the ntp.conf file.
Comment 4 Martin Prpič 2016-01-21 10:25:47 EST
Statement:

This issue affects the versions of ntp as shipped with Red Hat Enterprise Linux 5, 6, and 7. Red Hat Product Security has rated this issue as having Moderate security impact. A future update may address this issue in Red Hat Enterprise Linux 6 and 7. For additional information, refer to the Issue Severity Classification: https://access.redhat.com/security/updates/classification/.
Comment 5 Fedora Update System 2016-01-30 13:21:24 EST
ntp-4.2.6p5-36.fc23 has been pushed to the Fedora 23 stable repository. If problems still persist, please make note of it in this bug report.
Comment 6 Fedora Update System 2016-02-20 21:24:56 EST
ntp-4.2.6p5-36.fc22 has been pushed to the Fedora 22 stable repository. If problems still persist, please make note of it in this bug report.
Comment 9 errata-xmlrpc 2016-05-31 04:12:33 EDT
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 7
  Red Hat Enterprise Linux 6

Via RHSA-2016:1141 https://access.redhat.com/errata/RHSA-2016:1141
Comment 11 errata-xmlrpc 2016-08-03 03:43:33 EDT
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 6.7 Extended Update Support

Via RHSA-2016:1552 https://rhn.redhat.com/errata/RHSA-2016-1552.html
Comment 12 errata-xmlrpc 2016-11-03 15:33:39 EDT
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 7

Via RHSA-2016:2583 https://rhn.redhat.com/errata/RHSA-2016-2583.html

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