CVE-2016-1548: An attacker can spoof a packet from a legitimate ntpd server with an origin timestamp that matches the peer->dst timestamp recorded for that…
Noroxi assessment
Priority: Monitor (action score 29/100)
- The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
- Probability of exploitation in the next 30 days: 3.8% (FIRST EPSS); higher than 90.2% of all records.
- Anyone who can reach it over the internet can trigger it. No account or password is required. No user action is required. No special conditions are required; it is repeatable.
- Fixed version: ntp (Debian:11) 1:4.2.8p7+dfsg-1; ntp (Debian:7) 1:4.2.6.p5+dfsg-2+deb7u7; ntp (Debian:8) 1:4.2.6.p5+dfsg-7+deb8u2.
Low priority for now. Upgrade to ntp (Debian:11) 1:4.2.8p7+dfsg-1; ntp (Debian:7) 1:4.2.6.p5+dfsg-2+deb7u7; ntp (Debian:8) 1:4.2.6.p5+dfsg-7+deb8u2 or later.
Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it
Primary sources: NVD · CVE.org · FIRST EPSS
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.
- Published
- Jan 6, 2017
- Updated
- Jun 16, 2026
- EPSS
- 3.8% · 90th percentile
- CWE
- CWE-19
Report tools
Action score
29
Low priority for now.
- CVSS
- 28 / 40 · 7.2 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 1 / 30 · 3.8%
Get told when this record changes
- Not in KEV: no record of exploitation in the wild
- No public exploit code on record
- A fix has been released
If any of these changes, we'll tell you in the daily email digest.
Is your version affected? Check itNoroxi analysis
What does it mean in your environment?
The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.
We use this product, ask for helpAffected systems
Is your version affected?
Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.
| Vendor | Product | CPE |
|---|---|---|
| ntp | ntp | cpe:2.3:a:ntp:ntp |
Versions reported by the vendor
Affected version ranges reported by the assigning authority (certcc). Independent of NVD's CPE analysis and usually ahead of it.
NTP Project NTP
- 4.2.8p4affected
NTPsec Project NTPSec
- aa48d001683e5b791a743ec9c575aaf7d867a2b0caffected
Affected versions
NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.
- ntp ntp4.2.8
Package-level exposure
OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.
| Ecosystem | Package | Affected range | Fix |
|---|---|---|---|
| Debian:11 | ntp | before 1:4.2.8p7+dfsg-1 | 1:4.2.8p7+dfsg-1 |
| Debian:7 | ntp | before 1:4.2.6.p5+dfsg-2+deb7u7 | 1:4.2.6.p5+dfsg-2+deb7u7 |
| Debian:8 | ntp | before 1:4.2.6.p5+dfsg-7+deb8u2 | 1:4.2.6.p5+dfsg-7+deb8u2 |
| Red Hat:enterprise_linux:6::client | ntp | before 0:4.2.6p5-10.el6.1 | 0:4.2.6p5-10.el6.1 |
| Red Hat:enterprise_linux:6::client | ntp-debuginfo | before 0:4.2.6p5-10.el6.1 | 0:4.2.6p5-10.el6.1 |
| Red Hat:enterprise_linux:6::client | ntp-doc | before 0:4.2.6p5-10.el6.1 | 0:4.2.6p5-10.el6.1 |
| Red Hat:enterprise_linux:6::client | ntp-perl | before 0:4.2.6p5-10.el6.1 | 0:4.2.6p5-10.el6.1 |
| Red Hat:enterprise_linux:6::client | ntpdate | before 0:4.2.6p5-10.el6.1 | 0:4.2.6p5-10.el6.1 |
| Red Hat:enterprise_linux:7::client | ntp | before 0:4.2.6p5-22.el7_2.2 | 0:4.2.6p5-22.el7_2.2 |
| Red Hat:enterprise_linux:7::client | ntp-debuginfo | before 0:4.2.6p5-22.el7_2.2 | 0:4.2.6p5-22.el7_2.2 |
| Red Hat:enterprise_linux:7::client | ntp-doc | before 0:4.2.6p5-22.el7_2.2 | 0:4.2.6p5-22.el7_2.2 |
| Red Hat:enterprise_linux:7::client | ntp-perl | before 0:4.2.6p5-22.el7_2.2 | 0:4.2.6p5-22.el7_2.2 |
| Red Hat:enterprise_linux:7::client | ntpdate | before 0:4.2.6p5-22.el7_2.2 | 0:4.2.6p5-22.el7_2.2 |
| Red Hat:enterprise_linux:7::client | sntp | before 0:4.2.6p5-22.el7_2.2 | 0:4.2.6p5-22.el7_2.2 |
| Red Hat:rhel_eus:6.7::computenode | ntp | before 0:4.2.6p5-5.el6_7.5 | 0:4.2.6p5-5.el6_7.5 |
| Red Hat:rhel_eus:6.7::computenode | ntp-debuginfo | before 0:4.2.6p5-5.el6_7.5 | 0:4.2.6p5-5.el6_7.5 |
| Red Hat:rhel_eus:6.7::computenode | ntp-doc | before 0:4.2.6p5-5.el6_7.5 | 0:4.2.6p5-5.el6_7.5 |
| Red Hat:rhel_eus:6.7::computenode | ntp-perl | before 0:4.2.6p5-5.el6_7.5 | 0:4.2.6p5-5.el6_7.5 |
| Red Hat:rhel_eus:6.7::computenode | ntpdate | before 0:4.2.6p5-5.el6_7.5 | 0:4.2.6p5-5.el6_7.5 |
| SUSE:Linux Enterprise Desktop 12 | ntp | before 4.2.8p8-46.8.1 | 4.2.8p8-46.8.1 |
| SUSE:Linux Enterprise Server 11 SP4 | ntp | before 4.2.8p7-11.1 | 4.2.8p7-11.1 |
| SUSE:OpenStack Cloud 5 | ntp | before 4.2.8p7-44.1 | 4.2.8p7-44.1 |
Same product
ntp: all recordsOther highest-scoring records for the same primary product.
- CVE-2015-7871Crypto-NAK packets in ntpd in NTP 4.2.x before 4.2.8p4, and 4.3.x before 4.3.77 allows remote attackers to bypass authentication.64This week
- CVE-2014-9295Multiple stack-based buffer overflows in ntpd in NTP before 4.2.8 allow remote attackers to execute arbitrary code via a crafted packet…54Plan
- CVE-2013-5211The monlist feature in ntp_request.c in ntpd in NTP before 4.2.7p26 allows remote attackers to cause a denial of service (traffic…49Plan
Published before and after this one in the same product
- ← EarlierCVE-2015-7848Jan 6, 2017 · An integer overflow can occur in NTP-dev.4.3.70 leading to an out-of-bounds memory copy operation when processing a specially crafted…32Monitor
- ← EarlierCVE-2016-1547Jan 6, 2017 · An off-path attacker can cause a preemptible client association to be demobilized in NTP 4.2.8p4 and earlier and NTPSec…23Monitor
- Later →CVE-2016-1549Jan 6, 2017 · A malicious authenticated peer can create arbitrarily-many ephemeral associations in order to win the clock selection algorithm in ntpd in…27Monitor
Remediation
Which version to upgrade to
Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.
| Product / package | Fixed version | Source |
|---|---|---|
| debian:ntp | 1:4.2.8p7+dfsg-1 · Debian:11 | Package registry (OSV) |
| red hat:ntp | 0:4.2.6p5-10.el6.1 · Red Hat:enterprise_linux:6::client | Package registry (OSV) |
| red hat:ntp-debuginfo | 0:4.2.6p5-10.el6.1 · Red Hat:enterprise_linux:6::client | Package registry (OSV) |
| red hat:ntp-doc | 0:4.2.6p5-10.el6.1 · Red Hat:enterprise_linux:6::client | Package registry (OSV) |
| red hat:ntp-perl | 0:4.2.6p5-10.el6.1 · Red Hat:enterprise_linux:6::client | Package registry (OSV) |
| red hat:ntpdate | 0:4.2.6p5-10.el6.1 · Red Hat:enterprise_linux:6::client | Package registry (OSV) |
| red hat:sntp | 0:4.2.6p5-22.el7_2.2 · Red Hat:enterprise_linux:7::client | Package registry (OSV) |
| suse:ntp | 4.2.8p7-11.1 · SUSE:Linux Enterprise Server 11 SP4 | Package registry (OSV) |
Exploit status
No known public exploit
No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.
Research context
For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.
Timeline
From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.
No dated events beyond publication.
Not on record for this CVE: EPSS history · patch commit or PR link · researcher credit · variant or chain candidate · public bounty program.
Technical details
Attack conditions
- Anyone who can reach it over the internet can trigger it.
- No account or password is required.
- No user action is required.
- No special conditions are required; it is repeatable.
If successful
- Confidentiality
- none
- Integrity
- low · data or configuration can be modified
- Availability
- low · the service can be disrupted
Impact can extend beyond the vulnerable component (scope changes).
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- None
- User interaction
- None
- Scope
- Changed
- Confidentiality impact
- None
- Integrity impact
- Low
- Availability impact
- Low
Weakness class (CWE)
CWE-19 · Data Processing ErrorsCVSS vector
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:L
nvd-primary
Attack context
MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.
MITRE has no CAPEC/ATT&CK mapping for this CWE.
Change log (1)
- Fix✗ → ✓
For records you follow, these changes also arrive as notifications. →
References
Show all references (19 more)Show less
- lists.fedoraproject.org/pipermail/package-announce/2016-May/184669.html
- lists.opensuse.org/opensuse-security-announce/2016-05/msg00034.html
- lists.opensuse.org/opensuse-security-announce/2016-05/msg00037.html
- lists.opensuse.org/opensuse-security-announce/2016-05/msg00052.html
- lists.opensuse.org/opensuse-security-announce/2016-06/msg00001.html
- lists.opensuse.org/opensuse-security-announce/2016-06/msg00020.html
- lists.opensuse.org/opensuse-security-announce/2016-07/msg00026.html
- lists.opensuse.org/opensuse-security-announce/2016-08/msg00042.html
- lists.opensuse.org/opensuse-updates/2016-05/msg00114.html
- rhn.redhat.com/errata/RHSA-2016-1552.html
- tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20160428-ntpd
- www.debian.org/security/2016/dsa-3629
- www.oracle.com/technetwork/topics/security/bulletinapr2016-2952098.html
- www.oracle.com/technetwork/topics/security/linuxbulletinapr2016-2952096.html
- www.securityfocus.com/archive/1/538233/100/0/threaded
- www.securityfocus.com/archive/1/archive/1/538233/100/0/threaded
- www.securityfocus.com/bid/88264
- www.securitytracker.com/id/1035705
- www.ubuntu.com/usn/USN-3096-1
Vendor advisories and official records. Exploit/PoC links are deliberately left out.