What’s Vulnerable › Vulnerabilities

CVE-2016-9042

• Severity: medium (CVSS 5.9 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 3.9% probability of exploitation in the next 30 days
• Public exploit or detection template: yes
• Published: 2018-06-04 · updated 2026-06-17
• Weakness: CWE-20

Description

An exploitable denial of service vulnerability exists in the origin timestamp check functionality of ntpd 4.2.8p9. A specially crafted unauthenticated network packet can be used to reset the expected origin timestamp for target peers. Legitimate replies from targeted peers will fail the origin timestamp check (TEST2) causing the reply to be dropped and creating a denial of service condition.

Affected products

• FreeBSD: 10.0, 11.0
• HPE Hpux-Ntp: before c.4.2.8.4.0 — fixed in c.4.2.8.4.0
• NTP: 4.2.8-p9
• Siemens Simatic Net Cp 443-1 Opc Ua Firmware: all versions

How to fix

Upgrade to a fixed version: HPE Hpux-Ntp c.4.2.8.4.0. Check the vendor advisory for mitigations.

References

• http://packetstormsecurity.com/files/142101/FreeBSD-Security-Advisory-FreeBSD-SA-17-03.ntp.html
• http://packetstormsecurity.com/files/142284/Slackware-Security-Advisory-ntp-Updates.html
• http://seclists.org/fulldisclosure/2017/Nov/7
• http://seclists.org/fulldisclosure/2017/Sep/62
• http://www.securityfocus.com/archive/1/540403/100/0/threaded
• http://www.securityfocus.com/archive/1/archive/1/540403/100/0/threaded
• http://www.securityfocus.com/archive/1/archive/1/540464/100/0/threaded
• http://www.securityfocus.com/bid/97046
• http://www.securitytracker.com/id/1038123
• http://www.securitytracker.com/id/1039427
• http://www.ubuntu.com/usn/USN-3349-1
• https://bto.bluecoat.com/security-advisory/sa147

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