HIGH
ntp: ntpd switching to interleaved mode with spoofed packets
Published Jan 6, 2017
7.2
HIGHCVSS 3.0
EPSS 3.84%
Description
An attacker can spoof a packet from a legitimate ntpd server with an origin timestamp that matches the peer->dst timestamp recorded for that server. After making this switch, the client in NTP 4.2.8p4 and earlier and NTPSec aa48d001683e5b791a743ec9c575aaf7d867a2b0c will reject all future legitimate server responses. It is possible to force the victim client to move time after the mode has been changed. ntpq gives no indication that the mode has been switched.
Affected products
-
- Version 4.2.8p4StatusaffectedConstraints-
- Version
-
- Version aa48d001683e5b791a743ec9c575aaf7d867a2b0cStatusaffectedConstraints-
- 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 | ||||||
|---|---|---|---|---|---|---|---|---|---|
| NTP Project | NTP | n/a |
| ||||||
| NTPsec Project | NTPSec | n/a |
|
No data.
Red Hat Enterprise Linux 6
ntp-0:4.2.6p5-10.el6.1
Fixed · RHSA-2016:1141
Red Hat Enterprise Linux 6.7 Extended Update Support
ntp-0:4.2.6p5-5.el6_7.5
Fixed · RHSA-2016:1552
Red Hat Enterprise Linux 7
ntp-0:4.2.6p5-22.el7_2.2
Fixed · RHSA-2016:1141
Red Hat Enterprise Linux 5
ntp
Not affected
| Product | Package | State | Advisory |
|---|---|---|---|
| Red Hat Enterprise Linux 6 | ntp-0:4.2.6p5-10.el6.1 | Fixed | RHSA-2016:1141 |
| Red Hat Enterprise Linux 6.7 Extended Update Support | ntp-0:4.2.6p5-5.el6_7.5 | Fixed | RHSA-2016:1552 |
| Red Hat Enterprise Linux 7 | ntp-0:4.2.6p5-22.el7_2.2 | Fixed | RHSA-2016:1141 |
| Red Hat Enterprise Linux 5 | ntp | Not affected | n/a |
No package ranges for this CVE.
Remediation
No remediation recorded yet.
Metrics
No CVSS v4.0 score for this CVE.
No CVSS v3.1 score for this CVE.
7.2 HIGH NVD
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:L
Attack Vector Network
Attack Complexity Low
Privileges Required None
User Interaction None
Scope Changed
Confidentiality Impact None
Integrity Impact Low
Availability Impact Low
6.4 MEDIUM NVD
AV:N/AC:L/Au:N/C:N/I:P/A:P
Access Vector Network
Access Complexity Low
Authentication None
Confidentiality Impact None
Integrity Impact Partial
Availability Impact Partial
This CVE is not in the KEV list.
No CISA SSVC assessment for this CVE yet.
3.84% 0.03844
Estimated probability of exploitation in the wild in the next 30 days (FIRST EPSS). As of Oct 1, 2026.
EPSS probability 0.03844
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 (17 key points)
Flat stretches are collapsed; showing up to 120 newest points.
| Date | Score | Percentile | Model |
|---|---|---|---|
| Oct 1, 2026 | 3.84% (0.03844) | 89.80th | v5 (v2026.06.15) |
| Jun 15, 2026 | 3.84% (0.03844) | 88.72th | v5 (v2026.06.15) |
| May 3, 2026 | 5.40% (0.05403) | 90.17th | v4 (v2025.03.14) |
| Dec 28, 2025 | 2.76% (0.02762) | 85.58th | v4 (v2025.03.14) |
| Dec 27, 2025 | 1.65% (0.01653) | 81.62th | v4 (v2025.03.14) |
| Dec 20, 2025 | 2.76% (0.02762) | 85.56th | v4 (v2025.03.14) |
| Jun 3, 2025 | 1.70% (0.01705) | 81.46th | v4 (v2025.03.14) |
| Mar 30, 2025 | 2.90% (0.02900) | 85.12th | v4 (v2025.03.14) |
| Mar 29, 2025 | 6.53% (0.06529) | 84.79th | v4 (v2025.03.14) |
| Mar 17, 2025 | 2.30% (0.02299) | 83.59th | v4 (v2025.03.14) |
| Dec 12, 2024 | 0.62% (0.00618) | 79.51th | v3 (v2023.03.01) |
| Feb 29, 2024 | 0.62% (0.00618) | 78.27th | v3 (v2023.03.01) |
| Feb 8, 2024 | 0.55% (0.00548) | 76.76th | v3 (v2023.03.01) |
| Mar 7, 2023 | 0.55% (0.00548) | 73.94th | 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) |
Weaknesses (1)
References (40)
- http://lists.fedoraproject.org/pipermail/package-announce/2016-May/183647.html vendor-advisoryx_refsource_FEDORA
- http://lists.fedoraproject.org/pipermail/package-announce/2016-May/184669.html vendor-advisoryx_refsource_FEDORA
- http://lists.opensuse.org/opensuse-security-announce/2016-05/msg00034.html vendor-advisoryx_refsource_SUSE
- http://lists.opensuse.org/opensuse-security-announce/2016-05/msg00037.html vendor-advisoryx_refsource_SUSE
- http://lists.opensuse.org/opensuse-security-announce/2016-05/msg00052.html vendor-advisoryx_refsource_SUSE
- http://lists.opensuse.org/opensuse-security-announce/2016-06/msg00001.html vendor-advisoryx_refsource_SUSE
- http://lists.opensuse.org/opensuse-security-announce/2016-06/msg00020.html vendor-advisoryx_refsource_SUSE
- http://lists.opensuse.org/opensuse-security-announce/2016-07/msg00026.html vendor-advisoryx_refsource_SUSE
- http://lists.opensuse.org/opensuse-security-announce/2016-08/msg00042.html vendor-advisoryx_refsource_SUSE
- http://lists.opensuse.org/opensuse-updates/2016-05/msg00114.html vendor-advisoryx_refsource_SUSE
- http://packetstormsecurity.com/files/136864/Slackware-Security-Advisory-ntp-Updates.html x_refsource_MISC
- http://rhn.redhat.com/errata/RHSA-2016-1552.html vendor-advisoryx_refsource_REDHAT
- http://support.ntp.org/bin/view/Main/SecurityNotice#April_2016_NTP_4_2_8p7_Security
- http://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20160428-ntpd vendor-advisoryx_refsource_CISCO
- http://www.debian.org/security/2016/dsa-3629 vendor-advisoryx_refsource_DEBIAN
- http://www.oracle.com/technetwork/topics/security/bulletinapr2016-2952098.html x_refsource_CONFIRM
- http://www.oracle.com/technetwork/topics/security/linuxbulletinapr2016-2952096.html x_refsource_CONFIRM
- http://www.securityfocus.com/archive/1/538233/100/0/threaded mailing-listx_refsource_BUGTRAQ
- http://www.securityfocus.com/archive/1/archive/1/538233/100/0/threaded mailing-listx_refsource_BUGTRAQ
- http://www.securityfocus.com/bid/88264 vdb-entryx_refsource_BID
- http://www.securitytracker.com/id/1035705 vdb-entryx_refsource_SECTRACK
- http://www.talosintel.com/reports/TALOS-2016-0082/
- http://www.talosintelligence.com/reports/TALOS-2016-0082/ x_refsource_MISCExploitThird Party Advisory
- http://www.ubuntu.com/usn/USN-3096-1 vendor-advisoryx_refsource_UBUNTU
- https://access.redhat.com/errata/RHSA-2016:1141 vendor-advisoryx_refsource_REDHAT
- https://access.redhat.com/security/cve/CVE-2016-1548 Vendor Advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=1331462 Issue Tracking
- https://cert-portal.siemens.com/productcert/pdf/ssa-211752.pdf x_refsource_CONFIRM
- https://cert-portal.siemens.com/productcert/pdf/ssa-497656.pdf x_refsource_CONFIRM
- https://nvd.nist.gov/vuln/detail/CVE-2016-1548
- https://security.FreeBSD.org/advisories/FreeBSD-SA-16:16.ntp.asc vendor-advisoryx_refsource_FREEBSD
- https://security.gentoo.org/glsa/201607-15 vendor-advisoryx_refsource_GENTOO
- https://security.netapp.com/advisory/ntap-20171004-0002/ x_refsource_CONFIRM
- https://us-cert.cisa.gov/ics/advisories/icsa-21-103-11 x_refsource_MISC
- https://us-cert.cisa.gov/ics/advisories/icsa-21-159-11 x_refsource_MISC
- https://www.arista.com/en/support/advisories-notices/security-advisories/1332-security-advisory-19 x_refsource_MISC
- https://www.cve.org/CVERecord?id=CVE-2016-1548
- https://www.debian.org/security/2016/dsa-3629 vendor-advisoryx_refsource_DEBIAN
- https://www.kb.cert.org/vuls/id/718152 third-party-advisoryx_refsource_CERT-VN
- https://www.talosintelligence.com/vulnerability_reports/TALOS-2016-0082 x_refsource_MISC
Change history (0)
No recorded changes yet.
Sources
CVE.org / MITRE
Status PUBLISHED
Assigner certcc
Published Jan 6, 2017
Updated Aug 5, 2024
Reserved Jan 7, 2016
Link CVE-2016-1548
CISA Vulnrichment
Updated n/a