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
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Talos | Network Time Protocol | NTP 4.2.8p9 | — |
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 11 | ntp | 1:4.2.8p10+dfsg-1 | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 16.04 LTS | ntp | 1:4.2.8p4+dfsg-3ubuntu5.5 | USN-3349-1 |
| Ubuntu 14.04 LTS | ntp | 1:4.2.6.p5+dfsg-3ubuntu2.14.04.11 | USN-3349-1 |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 12 SP2 | ntp | 4.2.8p10-60.1 | SUSE-SU-2017:1048-1 |
| SLES 12 SP1 | ntp | 4.2.8p10-60.1 | SUSE-SU-2017:1048-1 |
| SLES 12 | ntp | 4.2.8p10-46.23.1 | SUSE-SU-2017:1047-1 |
| SLES 11 SP4 | ntp | 4.2.8p10-63.1 | SUSE-SU-2017:1052-1 |
Show 4 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES for SAP 12 SP2 | ntp | 4.2.8p10-60.1 | SUSE-SU-2017:1048-1 |
| SLES for SAP 12 SP1 | ntp | 4.2.8p10-60.1 | SUSE-SU-2017:1048-1 |
| SLES for SAP 12 | ntp | 4.2.8p10-46.23.1 | SUSE-SU-2017:1047-1 |
| SLES for SAP 11 SP4 | ntp | 4.2.8p10-63.1 | SUSE-SU-2017:1052-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | ntp | 4.2.8p15-7.2 | openSUSE-SU-2024:11102-1 |
Advisories 8
- USN-3349-1 ntp vulnerabilities Ubuntu Security Notices (USN) · Feb 10, 2026
- openSUSE-SU-2024:11102-1 ntp-4.2.8p15-7.2 on GA media SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2017:1048-1 Security update for ntp SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2017:1052-1 Security update for ntp SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2017:1047-1 Security update for ntp SUSE / openSUSE Security Updates · Feb 4, 2026
- ICSA-21-159-11 Siemens SIMATIC NET CP 443-1 OPC UA CISA ICS & IT advisories · May 6, 2025
- WID-SEC-2025-0370 Apple Mac OS: Mehrere Schwachstellen BSI CERT-Bund (WID) · Feb 13, 2025
- SSA-211752 SSA-211752: Multiple NTP-Client Related Vulnerabilities in SIMATIC CP 443-1 OPC UA Siemens ProductCERT · Feb 8, 2022
References
- 1038123 vdb-entry
- FreeBSD-SA-17:03 vendor-advisory
- 1039427 vdb-entry
- 97046 vdb-entry
- USN-3349-1 vendor-advisory
- 20170412 FreeBSD Security Advisory FreeBSD-SA-17:03.ntp mailing-list
- 20171101 APPLE-SA-2017-10-31-8 Additional information for APPLE-SA-2017-09-25-1 macOS High Sierra 10.13 mailing-list
- 20170412 FreeBSD Security Advisory FreeBSD-SA-17:03.ntp mailing-list
- FEDORA-2017-20d54b2782 vendor-advisory
- 20170925 APPLE-SA-2017-09-25-1 macOS High Sierra 10.13 mailing-list
- 20170422 [slackware-security] ntp (SSA:2017-112-02) mailing-list
- https://support.hpe.com/hpsc/doc/public/display?docLocale=en_US&docId=emr_na-hpesbux03962en_us
- https://www.talosintelligence.com/vulnerability_reports/TALOS-2016-0260
- http://packetstormsecurity.com/files/142101/FreeBSD-Security-Advisory-FreeBSD-SA-17-03.ntp.html
- https://kc.mcafee.com/corporate/index?page=content&id=SB10201
- https://support.apple.com/kb/HT208144
- https://support.f5.com/csp/article/K39041624
- https://bto.bluecoat.com/security-advisory/sa147
- http://packetstormsecurity.com/files/142284/Slackware-Security-Advisory-ntp-Updates.html
- https://cert-portal.siemens.com/productcert/pdf/ssa-211752.pdf
- https://us-cert.cisa.gov/ics/advisories/icsa-21-159-11