CVE-2016-4957

ntpd in NTP before 4.2.8p8 allows remote attackers to cause a denial of service (daemon crash) via a crypto-NAK packet. NOTE: this vulnerability exists because of an incorrect fix for CVE-2016-1547.

Published: Jul 5, 2016
Updated: Nov 9, 2025
CVE: CVE-2016-4957
Severity: High
Exploit:

CVSS v3:

Severity: High
Score: 7.5
AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CVSS v2:

Severity: Medium
Score: 5
AV:N/AC:L/Au:N/C:N/I:N/A:P

CWEs:

CWE-476

Affected Software
References

Software	From	Fixed in
ntp / ntp	4.3.92	4.3.92.x
ntp / ntp	4.2.8-p7	4.2.8-p7.x
oracle / solaris	11.3	11.3.x
oracle / solaris	10	10.x
novell / suse_manager	2.1	2.1.x
suse / linux_enterprise_server	11-sp4	11-sp4.x
suse / openstack_cloud	5	5.x
suse / manager_proxy	2.1	2.1.x
suse / linux_enterprise_server	11-sp3	11-sp3.x
suse / linux_enterprise_server	12-sp1	12-sp1.x
suse / linux_enterprise_server	11-sp2	11-sp2.x
suse / linux_enterprise_desktop	12-sp1	12-sp1.x
opensuse / leap	42.1	42.1.x
opensuse / opensuse	13.2	13.2.x

http://bugs.ntp.org/3046
http://lists.opensuse.org/opensuse-security-announce/2016-06/msg00018.html
http://lists.opensuse.org/opensuse-security-announce/2016-06/msg00023.html
http://lists.opensuse.org/opensuse-security-announce/2016-06/msg00024.html
http://lists.opensuse.org/opensuse-security-announce/2016-06/msg00028.html
http://lists.opensuse.org/opensuse-security-announce/2016-06/msg00040.html
http://support.ntp.org/bin/view/Main/NtpBug3046
http://support.ntp.org/bin/view/Main/SecurityNotice
http://www.kb.cert.org/vuls/id/321640
http://www.oracle.com/technetwork/topics/security/bulletinapr2016-2952098.html
http://www.securitytracker.com/id/1036037
https://security.FreeBSD.org/advisories/FreeBSD-SA-16:24.ntp.asc
https://security.gentoo.org/glsa/201607-15

Vulnerability Database

300,445

CVE-2016-4957

Deep Security Visibility Without the Complexity