CVE-2016-4955

moderate-risk
Published 2016-07-05

ntpd in NTP 4.x before 4.2.8p8, when autokey is enabled, allows remote attackers to cause a denial of service (peer-variable clearing and association outage) by sending (1) a spoofed crypto-NAK packet or (2) a packet with an incorrect MAC value at a certain time.

Do I need to act?

~
1.9% chance of exploitation in next 30 days
EPSS score — moderate exploit probability
-
Not on CISA KEV list
No confirmed active exploitation reported to CISA
?
Patch status unknown
Check vendor advisories for fix availability and mitigation guidance
5
CVSS 5.9/10 Medium
NETWORK / HIGH complexity

Affected Products (20)

Ntp
Ntp
Ntp
Ntp
Ntp
Ntp
Ntp
Ntp
Ntp
Ntp
Ntp
Suse Manager
Ntp
Ntp
Ntp
Ntp

Affected Vendors

Siemens Ntp Oracle Opensuse Novell Suse

References (62)

Issue Tracking http://bugs.ntp.org/3043
Mailing List http://lists.opensuse.org/opensuse-security-announce/2016-06/msg00018.html
http://lists.opensuse.org/opensuse-security-announce/2016-06/msg00020.html
Mailing List http://lists.opensuse.org/opensuse-security-announce/2016-06/msg00023.html
Mailing List http://lists.opensuse.org/opensuse-security-announce/2016-06/msg00024.html
Mailing List http://lists.opensuse.org/opensuse-security-announce/2016-06/msg00028.html
Mailing List http://lists.opensuse.org/opensuse-security-announce/2016-06/msg00040.html
http://lists.opensuse.org/opensuse-security-announce/2016-07/msg00026.html
http://lists.opensuse.org/opensuse-security-announce/2016-08/msg00042.html
http://packetstormsecurity.com/files/137321/Slackware-Security-Advisory-ntp-Upda...
http://packetstormsecurity.com/files/137322/FreeBSD-Security-Advisory-FreeBSD-SA...
Patch http://support.ntp.org/bin/view/Main/NtpBug3043
Release Notes http://support.ntp.org/bin/view/Main/SecurityNotice
http://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20...
Third Party Advisory http://www.kb.cert.org/vuls/id/321640
Third Party Advisory http://www.oracle.com/technetwork/topics/security/bulletinapr2016-2952098.html
http://www.securityfocus.com/archive/1/538599/100/0/threaded
http://www.securityfocus.com/archive/1/538600/100/0/threaded
http://www.securityfocus.com/archive/1/archive/1/538599/100/0/threaded
http://www.securityfocus.com/archive/1/archive/1/538600/100/0/threaded
and 42 more references
46
/ 100
moderate-risk
Severity 18/34 · Moderate
Exploitability 5/34 · Minimal
Exposure 23/34 · High