Bug 1686605 (CVE-2019-8936) - CVE-2019-8936 ntp: Crafted null dereference attack in authenticated mode 6 packet
Summary: CVE-2019-8936 ntp: Crafted null dereference attack in authenticated mode 6 pa...
Keywords:
Status: CLOSED NOTABUG
Alias: CVE-2019-8936
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
medium
medium
Target Milestone: ---
Assignee: Red Hat Product Security
QA Contact:
URL:
Whiteboard:
Depends On: 1686606
Blocks: 1686608
TreeView+ depends on / blocked
 
Reported: 2019-03-07 20:01 UTC by Pedro Sampaio
Modified: 2021-02-16 22:17 UTC (History)
16 users (show)

Fixed In Version: ntp 4.2.8p13
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Environment:
Last Closed: 2019-03-11 10:17:44 UTC
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Description Pedro Sampaio 2019-03-07 20:01:11 UTC 
A flaw was found in ntp before version 4.2.8p13. An authenticated attacker can cause ntpd to sigsegv by triggering a NULL pointer exception.

Upstream issue:

http://bugs.ntp.org/show_bug.cgi?id=3565

Upstream patch:

http://bk.ntp.org/ntp-stable/ntpd/ntp_control.c?PAGE=diffs&REV=5c8106e7wWtXdh0lzg1ytlWribBTcQ

References:

https://gitlab.com/NTPsec/ntpsec/issues/509
Comment 1 Pedro Sampaio 2019-03-07 20:01:29 UTC 
Created ntp tracking bugs for this issue:

Affects: fedora-all [bug 1686606]
Comment 2 Stefan Cornelius 2019-03-08 16:22:32 UTC 
Although the RHEL7 version is missing the NULL checks added in this patch, it does not crash with the POC provided. It seems like this was introduced in later versions due to changes in the ctl_getitem() function in ntpd/ntp_control.c, which are not yet part of the RHEL7 version.
Comment 4 Stefan Cornelius 2019-03-11 10:17:55 UTC 
Statement:

This issue did not affect the versions of ntp as shipped with Red Hat Enterprise Linux 5, 6, and 7.
Comment 5 Fedora Update System 2019-04-07 00:01:01 UTC 
ntp-4.2.8p13-1.fc30 has been pushed to the Fedora 30 stable repository. If problems still persist, please make note of it in this bug report.
Comment 6 Fedora Update System 2019-04-07 01:47:12 UTC 
ntp-4.2.8p13-1.fc28 has been pushed to the Fedora 28 stable repository. If problems still persist, please make note of it in this bug report.
Comment 7 Fedora Update System 2019-04-07 04:19:34 UTC 
ntp-4.2.8p13-1.fc29 has been pushed to the Fedora 29 stable repository. If problems still persist, please make note of it in this bug report.
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