PT-2016-6186 · Cisco+3 · Ntp+6

Jakub Prokes + 1 · Published 2016-06-03 · Updated 2024-06-15 · CVE-2016-4953

Positive Technologies (AI Summary)

CVSS v3.1

7.5

High

Base vector

AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Name of the Vulnerable Software and Affected Versions NTP versions 4.x before 4.2.8p8

Description The issue allows remote attackers to cause a denial of service (ephemeral-association demobilization) by sending a spoofed crypto-NAK packet with incorrect authentication data at a certain time. Multiple Cisco products that incorporate a version of the Network Time Protocol daemon (ntpd) package are affected, which could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition or modify the time being advertised by a device acting as a Network Time Protocol (NTP) server.

Recommendations For NTP versions 4.x before 4.2.8p8, update to version 4.2.8p8 or later to resolve the issue. As a temporary workaround, consider restricting access to the ntpd package to minimize the risk of exploitation. Avoid using the crypto-NAK packet in the affected NTP protocol until the issue is resolved. Restrict access to the vulnerable ntpd package to minimize the risk of exploitation.

Fix

DoS

Improper Authentication

Weakness Enumeration

CWE-287

Related Identifiers

ALT-PU-2017-2335

CVE-2016-4953

FREEBSD-SA-16_24

OPENSUSE-SU-2016_1583-1

OPENSUSE-SU-2016_1636-1

OPENSUSE-SU-2024:10181-1

SUSE-SU-2016:1563-1

SUSE-SU-2016:1568-1

SUSE-SU-2016:1584-1

SUSE-SU-2016:1602-1

SUSE-SU-2016_1563-1

SUSE-SU-2016_1584-1

SUSE-SU-2016_1602-1

Affected Products

Alt Linux

Cisco Ios

Cisco Ios Xr

Cisco Nexus

Freebsd

Ntp

Suse

References · 127

• https://security.gentoo.org/glsa/201607-15 · Vendor Advisory
• https://osv.dev/vulnerability/CVE-2016-4953 · Vendor Advisory
• http://bugs.ntp.org/3045 · Vendor Advisory
• http://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20160603-ntpd · Vendor Advisory
• http://lists.opensuse.org/opensuse-security-announce/2016-06/msg00018.html · Vendor Advisory
• https://security-tracker.debian.org/tracker/CVE-2016-4953 · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2016-4953 · Security Note
• http://support.ntp.org/bin/view/Main/SecurityNotice · Vendor Advisory
• https://osv.dev/vulnerability/SUSE-SU-2016:1584-1 · Vendor Advisory
• https://osv.dev/vulnerability/SUSE-SU-2016:1563-1 · Vendor Advisory
• http://lists.opensuse.org/opensuse-security-announce/2016-06/msg00028.html · Vendor Advisory
• https://security.freebsd.org/advisories/FreeBSD-SA-16:24.ntp.asc · Vendor Advisory
• http://support.ntp.org/bin/view/Main/NtpBug3045 · Vendor Advisory
• http://lists.opensuse.org/opensuse-security-announce/2016-06/msg00040.html · Vendor Advisory
• http://lists.opensuse.org/opensuse-security-announce/2016-07/msg00026.html · Vendor Advisory