ntp: DoS via origin timestamp check functionality
Published Jun 4, 2018
5.9
MEDIUMCVSS 3.1
EPSS 3.91%
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
-
- Version NTP 4.2.8p9StatusaffectedConstraints-
- Version
Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).
| Vendor | Product | Default status | Versions | ||||||
|---|---|---|---|---|---|---|---|---|---|
| Talos | Network Time Protocol | n/a |
|
Configuration 3
- < c.4.2.8.4.0
Configuration 4
Running on/with
- n/a
No data.
Red Hat Enterprise Linux 5
ntp
Not affected
Red Hat Enterprise Linux 6
ntp
Not affected
Red Hat Enterprise Linux 7
ntp
Not affected
| Product | Package | State | Advisory |
|---|---|---|---|
| Red Hat Enterprise Linux 5 | ntp | Not affected | n/a |
| Red Hat Enterprise Linux 6 | ntp | Not affected | n/a |
| Red Hat Enterprise Linux 7 | ntp | Not affected | n/a |
No package ranges for this CVE.
Remediation
Red Hat mitigation
Implement BCP-38. Configure enough servers/peers that an attacker cannot target all of your time sources. Properly monitor your ntpd instances, and auto-restart ntpd (without -g) if it stops running.
Metrics
No CVSS v4.0 score for this CVE.
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
1 other source (CVE.org) ▾
CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L
AV:N/AC:M/Au:N/C:N/I:N/A:P
This CVE is not in the KEV list.
No CISA SSVC assessment for this CVE yet.
Estimated probability of exploitation in the wild in the next 30 days (FIRST EPSS). As of Oct 1, 2026.
Score over time
2022–2026- EPSS v2
- EPSS v3
- EPSS v4
- EPSS v5
Percentile over time
- EPSS v2
- EPSS v3
- EPSS v4
- EPSS v5
Table of values (23 key points)
Flat stretches are collapsed; showing up to 120 newest points.
| Date | Score | Percentile | Model |
|---|---|---|---|
| Oct 1, 2026 | 3.91% (0.03910) | 89.96th | v5 (v2026.06.15) |
| Jun 15, 2026 | 3.96% (0.03960) | 89.06th | v5 (v2026.06.15) |
| May 15, 2026 | 1.78% (0.01777) | 82.88th | v4 (v2025.03.14) |
| May 4, 2026 | 3.31% (0.03307) | 87.30th | v4 (v2025.03.14) |
| Dec 28, 2025 | 4.84% (0.04844) | 89.18th | v4 (v2025.03.14) |
| Dec 27, 2025 | 2.53% (0.02529) | 85.08th | v4 (v2025.03.14) |
| Dec 20, 2025 | 4.84% (0.04844) | 89.16th | v4 (v2025.03.14) |
| Dec 18, 2025 | 3.51% (0.03507) | 87.23th | v4 (v2025.03.14) |
| Dec 14, 2025 | 5.24% (0.05238) | 89.61th | v4 (v2025.03.14) |
| Apr 21, 2025 | 3.34% (0.03336) | 86.59th | v4 (v2025.03.14) |
| Mar 24, 2025 | 1.91% (0.01909) | 81.65th | v4 (v2025.03.14) |
| Mar 17, 2025 | 0.72% (0.00717) | 70.72th | v4 (v2025.03.14) |
| Dec 17, 2024 | 4.00% (0.03996) | 91.96th | v3 (v2023.03.01) |
| Dec 12, 2024 | 1.86% (0.01865) | 88.87th | v3 (v2023.03.01) |
| Mar 1, 2024 | 2.04% (0.02044) | 88.66th | v3 (v2023.03.01) |
| Feb 8, 2024 | 1.92% (0.01922) | 88.19th | v3 (v2023.03.01) |
| Oct 26, 2023 | 1.66% (0.01662) | 86.20th | v3 (v2023.03.01) |
| Oct 4, 2023 | 2.70% (0.02699) | 89.24th | v3 (v2023.03.01) |
| May 29, 2023 | 5.25% (0.05252) | 91.84th | v3 (v2023.03.01) |
| Mar 7, 2023 | 6.18% (0.06181) | 92.38th | v3 (v2023.03.01) |
| Mar 6, 2023 | 2.69% (0.02686) | 82.85th | v2 (v2022.01.01) |
| Apr 1, 2022 | 2.69% (0.02686) | 81.17th | v2 (v2022.01.01) |
| Feb 4, 2022 | 2.69% (0.02686) | 62.66th | v2 (v2022.01.01) |
References (26)
- http://packetstormsecurity.com/files/142101/FreeBSD-Security-Advisory-FreeBSD-SA-17-03.ntp.html x_refsource_MISC
- http://packetstormsecurity.com/files/142284/Slackware-Security-Advisory-ntp-Updates.html x_refsource_MISC
- http://seclists.org/fulldisclosure/2017/Nov/7 mailing-listx_refsource_FULLDISC
- http://seclists.org/fulldisclosure/2017/Sep/62 mailing-listx_refsource_FULLDISC
- http://www.securityfocus.com/archive/1/540403/100/0/threaded mailing-listx_refsource_BUGTRAQ
- http://www.securityfocus.com/archive/1/archive/1/540403/100/0/threaded mailing-listx_refsource_BUGTRAQ
- http://www.securityfocus.com/archive/1/archive/1/540464/100/0/threaded mailing-listx_refsource_BUGTRAQ
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- http://www.securitytracker.com/id/1039427 vdb-entryx_refsource_SECTRACKThird Party AdvisoryVDB Entry
- http://www.talosintelligence.com/reports/TALOS-2016-0260/
- http://www.ubuntu.com/usn/USN-3349-1 vendor-advisoryx_refsource_UBUNTU
- https://access.redhat.com/security/cve/CVE-2016-9042 Vendor Advisory
- https://bto.bluecoat.com/security-advisory/sa147 x_refsource_CONFIRM
- https://bugzilla.redhat.com/show_bug.cgi?id=1434017 Issue Tracking
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- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/7KVLFA3J43QFIP4I7HE7KQ5FXSMJEKC6/ vendor-advisoryx_refsource_FEDORA
- https://nvd.nist.gov/vuln/detail/CVE-2016-9042
- https://security.FreeBSD.org/advisories/FreeBSD-SA-17:03.ntp.asc vendor-advisoryx_refsource_FREEBSDThird Party Advisory
- https://support.apple.com/kb/HT208144 x_refsource_CONFIRM
- https://support.f5.com/csp/article/K39041624 x_refsource_CONFIRM
- https://support.hpe.com/hpsc/doc/public/display?docLocale=en_US&docId=emr_na-hpesbux03962en_us x_refsource_CONFIRMThird Party Advisory
- https://us-cert.cisa.gov/ics/advisories/icsa-21-159-11 x_refsource_MISC
- https://www.cve.org/CVERecord?id=CVE-2016-9042
- https://www.talosintelligence.com/vulnerability_reports/TALOS-2016-0260 x_refsource_MISCExploitMitigationThird Party Advisory
Change history (0)
No recorded changes yet.