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CVE-2018-7170

ntpd in ntp 4.2.x before 4.2.8p7 and 4.3.x before 4.3.92 allows authenticated users that know the...

5.3 MediumFix available

ntpd in ntp 4.2.x before 4.2.8p7 and 4.3.x before 4.3.92 allows authenticated users that know the private symmetric key to create arbitrarily-many ephemeral associations in order to win the clock selection of ntpd and modify a victim's clock via a Sybil attack. This issue exists because of an incomplete fix for CVE-2016-1549.

Attack profile

How easy it is to exploit

Attack vector
Network
Complexity
High
Privileges needed
Low
User interaction
None

What an attacker can affect

Confidentiality
None
Integrity
High
Availability
None

Exploit likelihood

2.69%Up 0.4 points since Apr 14, 2021
90%50%10%1%

What each source reports

NVD Score used 5.3

ntpd in ntp 4.2.x before 4.2.8p7 and 4.3.x before 4.3.92 allows authenticated users that know the private symmetric key to create arbitrarily-many ephemeral associations in order to win the clock selection of ntpd and modify a victim's clock via a Sybil attack. This issue exists because of an incomplete fix for CVE-2016-1549.

Record
CVE-2018-7170
CVSS 3.1
5.3 MediumCVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:H/A:N
CVSS 2.0
3.5 LowAV:N/AC:M/Au:S/C:N/I:P/A:N
Updated
2026-11-02
CVE List No score

ntpd in ntp 4.2.x before 4.2.8p7 and 4.3.x before 4.3.92 allows authenticated users that know the private symmetric key to create arbitrarily-many ephemeral associations in order to win the clock selection of ntpd and modify a victim's clock via a Sybil attack. This issue exists because of an incomplete fix for CVE-2016-1549.

Record
CVE-2018-7170
Updated
2026-11-02
EUVDEUVD-2018-18912 No score

ntpd in ntp 4.2.x before 4.2.8p7 and 4.3.x before 4.3.92 allows authenticated users that know the private symmetric key to create arbitrarily-many ephemeral associations in order to win the clock selection of ntpd and modify a victim's clock via a Sybil attack. This issue exists because of an incomplete fix for CVE-2016-1549.

Record
EUVD-2018-18912
Updated
2026-11-03
GitHub AdvisoriesGHSA-v9cv-3r4j-cx4j 5.3

ntpd in ntp 4.2.x before 4.2.8p7 and 4.3.x before 4.3.92 allows authenticated users that know the...

ntpd in ntp 4.2.x before 4.2.8p7 and 4.3.x before 4.3.92 allows authenticated users that know the private symmetric key to create arbitrarily-many ephemeral associations in order to win the clock selection of ntpd and modify a victim's clock via a Sybil attack. This issue exists because of an incomplete fix for CVE-2016-1549.

Record
GHSA-v9cv-3r4j-cx4j
CVSS 3.1
5.3 MediumCVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:H/A:N
Updated
2026-11-02
OSV 5.3

ntpd in ntp 4.2.x before 4.2.8p7 and 4.3.x before 4.3.92 allows authenticated users that know the private symmetric key to create arbitrarily-many ephemeral associations in order to win the clock selection of ntpd and modify a victim's clock via a Sybil attack. This issue exists because of an incomplete fix for CVE-2016-1549.

Record
CVE-2018-7170
CVSS 3.1
5.3 MediumCVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:H/A:N
Updated
2026-11-02
OSVDEBIAN-CVE-2018-7170 5.3

ntpd in ntp 4.2.x before 4.2.8p7 and 4.3.x before 4.3.92 allows authenticated users that know the private symmetric key to create arbitrarily-many ephemeral associations in order to win the clock selection of ntpd and modify a victim's clock via a Sybil attack. This issue exists because of an incomplete fix for CVE-2016-1549.

Record
DEBIAN-CVE-2018-7170
CVSS 3.1
5.3 MediumCVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:H/A:N
Updated
2026-11-02
Show 14 moreShow less
OSVUBUNTU-CVE-2018-7170 5.3

ntpd in ntp 4.2.x before 4.2.8p7 and 4.3.x before 4.3.92 allows authenticated users that know the private symmetric key to create arbitrarily-many ephemeral associations in order to win the clock selection of ntpd and modify a victim's clock via a Sybil attack. This issue exists because of an incomplete fix for CVE-2016-1549.

Record
UBUNTU-CVE-2018-7170
CVSS 3.1
5.3 MediumCVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:H/A:N
Updated
2026-11-02
OSVMGASA-2018-0195 No score

Updated ntp packages fix security vulnerabilities

This release addresses five security issues in ntpd for Mageia 6:

LOW/MEDIUM: Sec 3012 / CVE-2016-1549 / VU#961909: Sybil vulnerability: ephemeral association attack While fixed in ntp-4.2.8p7, there are significant additional protections for this issue in 4.2.8p11. Reported by Matt Van Gundy of Cisco.

INFO/MEDIUM: Sec 3412 / CVE-2018-7182 / VU#961909: ctl_getitem(): buffer read overrun leads to undefined behavior and information leak Reported by Yihan Lian of Qihoo 360.

LOW: Sec 3415 / CVE-2018-7170 / VU#961909: Multiple authenticated ephemeral associations. Reported on the questions@ list.

LOW: Sec 3453 / CVE-2018-7184 / VU#961909: Interleaved symmetric mode cannot recover from bad state. Reported by Miroslav Lichvar of Red Hat.

LOW/MEDIUM: Sec 3454 / CVE-2018-7185 / VU#961909: Unauthenticated packet can reset authenticated interleaved association. Reported by Miroslav Lichvar of Red Hat.

one security issue in ntpq: MEDIUM: Sec 3414 / CVE-2018-7183 / VU#961909: ntpq:decodearr() can write beyond its buffer limit. Reported by Michael Macnair of Thales-esecurity.com.

and provides over 33 bugfixes and 32 other improvements. ENotification of these issues were delivered to our Institutional members on a rolling basis as they were reported and as progress was made.

Record
MGASA-2018-0195
Updated
2026-11-02
OSVopenSUSE-SU-2024:11102-1 No score

ntp-4.2.8p15-7.2 on GA media

These are all security issues fixed in the ntp-4.2.8p15-7.2 package on the GA media of openSUSE Tumbleweed.

Record
openSUSE-SU-2024:11102-1
Updated
2026-11-02
OSVSUSE-SU-2018:0808-1 No score

Security update for ntp

This update for ntp fixes the following issues:

Security issues fixed:

  • CVE-2016-1549: Significant additional protections against CVE-2016-1549 that was fixed in ntp-4.2.8p7 (bsc#1082210).
  • CVE-2018-7170: Ephemeral association time spoofing additional protection (bsc#1083424).
  • CVE-2018-7182: Buffer read overrun leads information leak in ctl_getitem() (bsc#1083426).
  • CVE-2018-7183: decodearr() can write beyond its buffer limit (bsc#1083417).
  • CVE-2018-7184: Interleaved symmetric mode cannot recover from bad state (bsc#1083422).
  • CVE-2018-7185: Unauthenticated packet can reset authenticated interleaved association (bsc#1083420).

Bug fixes:

  • bsc#1077445: Don't use libevent's cached time stamps in sntp.
  • Disable CMAC in ntp when building against a version of OpenSSL that doesn't support it.
Record
SUSE-SU-2018:0808-1
Updated
2026-11-02
OSVSUSE-SU-2018:0956-1 No score

Security update for ntp

This update for ntp fixes the following issues:

  • Update to 4.2.8p11 (bsc#1082210):
    • CVE-2016-1549: Sybil vulnerability: ephemeral association attack. While fixed in ntp-4.2.8p7, there are significant additional protections for this issue in 4.2.8p11.
    • CVE-2018-7182: ctl_getitem(): buffer read overrun leads to undefined behavior and information leak. (bsc#1083426)
    • CVE-2018-7170: Multiple authenticated ephemeral associations. (bsc#1083424)
    • CVE-2018-7184: Interleaved symmetric mode cannot recover from bad state. (bsc#1083422)
    • CVE-2018-7185: Unauthenticated packet can reset authenticated interleaved association. (bsc#1083420)
    • CVE-2018-7183: ntpq:decodearr() can write beyond its buffer limit.(bsc#1083417)
  • Don't use libevent's cached time stamps in sntp. (bsc#1077445)
Record
SUSE-SU-2018:0956-1
Updated
2026-11-02
OSVSUSE-SU-2018:1464-1 No score

Security update for ntp

This update for ntp fixes the following issues:

  • Update to 4.2.8p11 (bsc#1082210):
    • CVE-2016-1549: Sybil vulnerability: ephemeral association attack. While fixed in ntp-4.2.8p7, there are significant additional protections for this issue in 4.2.8p11.
    • CVE-2018-7182: ctl_getitem(): buffer read overrun leads to undefined behavior and information leak. (bsc#1083426)
    • CVE-2018-7170: Multiple authenticated ephemeral associations. (bsc#1083424)
    • CVE-2018-7184: Interleaved symmetric mode cannot recover from bad state. (bsc#1083422)
    • CVE-2018-7185: Unauthenticated packet can reset authenticated interleaved association. (bsc#1083420)
    • CVE-2018-7183: ntpq:decodearr() can write beyond its buffer limit.(bsc#1083417)
  • Don't use libevent's cached time stamps in sntp. (bsc#1077445)
  • Fix systemd migration in %pre (bsc#1034892).
Record
SUSE-SU-2018:1464-1
Updated
2026-11-02
OSVSUSE-SU-2018:1765-1 No score

Security update for ntp

This update for ntp fixes the following issues:

  • Update to 4.2.8p11 (bsc#1082210):
    • CVE-2016-1549: Sybil vulnerability: ephemeral association attack. While fixed in ntp-4.2.8p7, there are significant additional protections for this issue in 4.2.8p11.
    • CVE-2018-7182: ctl_getitem(): buffer read overrun leads to undefined behavior and information leak. (bsc#1083426)
    • CVE-2018-7170: Multiple authenticated ephemeral associations. (bsc#1083424)
    • CVE-2018-7184: Interleaved symmetric mode cannot recover from bad state. (bsc#1083422)
    • CVE-2018-7185: Unauthenticated packet can reset authenticated interleaved association. (bsc#1083420)
    • CVE-2018-7183: ntpq:decodearr() can write beyond its buffer limit.(bsc#1083417)
  • Don't use libevent's cached time stamps in sntp. (bsc#1077445)

This update is a reissue of the previous update with LTSS channels included.

Record
SUSE-SU-2018:1765-1
Updated
2026-11-02
OSVSUSE-SU-2018:1765-2 No score

Security update for ntp

This update for ntp fixes the following issues:

  • Update to 4.2.8p11 (bsc#1082210):
    • CVE-2016-1549: Sybil vulnerability: ephemeral association attack. While fixed in ntp-4.2.8p7, there are significant additional protections for this issue in 4.2.8p11.
    • CVE-2018-7182: ctl_getitem(): buffer read overrun leads to undefined behavior and information leak. (bsc#1083426)
    • CVE-2018-7170: Multiple authenticated ephemeral associations. (bsc#1083424)
    • CVE-2018-7184: Interleaved symmetric mode cannot recover from bad state. (bsc#1083422)
    • CVE-2018-7185: Unauthenticated packet can reset authenticated interleaved association. (bsc#1083420)
    • CVE-2018-7183: ntpq:decodearr() can write beyond its buffer limit.(bsc#1083417)
  • Don't use libevent's cached time stamps in sntp. (bsc#1077445)

This update is a reissue of the previous update with LTSS channels included.

Record
SUSE-SU-2018:1765-2
Updated
2026-11-02
OSVSUSE-SU-2018:3342-1 No score

Security update for ntp

NTP was updated to 4.2.8p12 (bsc#1111853):

  • CVE-2018-12327: Fixed stack buffer overflow in the openhost() command-line call of NTPQ/NTPDC. (bsc#1098531)
  • CVE-2018-7170: Add further tweaks to improve the fix for the ephemeral association time spoofing additional protection (bsc#1083424)

Please also see https://www.nwtime.org/network-time-foundation-publishes-ntp-4-2-8p12/ for more information.

Record
SUSE-SU-2018:3342-1
Updated
2026-11-02
OSVSUSE-SU-2018:3342-2 No score

Security update for ntp

NTP was updated to 4.2.8p12 (bsc#1111853):

  • CVE-2018-12327: Fixed stack buffer overflow in the openhost() command-line call of NTPQ/NTPDC. (bsc#1098531)
  • CVE-2018-7170: Add further tweaks to improve the fix for the ephemeral association time spoofing additional protection (bsc#1083424)

Please also see https://www.nwtime.org/network-time-foundation-publishes-ntp-4-2-8p12/ for more information.

Record
SUSE-SU-2018:3342-2
Updated
2026-11-02
OSVSUSE-SU-2018:3351-1 No score

Security update for ntp

NTP was updated to 4.2.8p12 (bsc#1111853):

  • CVE-2018-12327: Fixed stack buffer overflow in the openhost() command-line call of NTPQ/NTPDC. (bsc#1098531)
  • CVE-2018-7170: Add further tweaks to improve the fix for the ephemeral association time spoofing additional protection (bsc#1083424)

Please also see https://www.nwtime.org/network-time-foundation-publishes-ntp-4-2-8p12/ for more information.

Record
SUSE-SU-2018:3351-1
Updated
2026-11-02
OSVSUSE-SU-2018:3352-1 No score

Security update for ntp

NTP was updated to 4.2.8p12 (bsc#1111853):

  • CVE-2018-12327: Fixed stack buffer overflow in the openhost() command-line call of NTPQ/NTPDC. (bsc#1098531)
  • CVE-2018-7170: Add further tweaks to improve the fix for the ephemeral association time spoofing additional protection (bsc#1083424)

Please also see https://www.nwtime.org/network-time-foundation-publishes-ntp-4-2-8p12/ for more information.

Record
SUSE-SU-2018:3352-1
Updated
2026-11-02
OSVSUSE-SU-2018:3356-1 No score

Security update for ntp

NTP was updated to 4.2.8p12 (bsc#1111853):

  • CVE-2018-12327: Fixed stack buffer overflow in the openhost() command-line call of NTPQ/NTPDC. (bsc#1098531)
  • CVE-2018-7170: Add further tweaks to improve the fix for the ephemeral association time spoofing additional protection (bsc#1083424)

Please also see https://www.nwtime.org/network-time-foundation-publishes-ntp-4-2-8p12/ for more information.

Record
SUSE-SU-2018:3356-1
Updated
2026-11-02
OSVSUSE-SU-2018:3386-1 No score

Security update for ntp

NTP was updated to 4.2.8p12 (bsc#1111853):

  • CVE-2018-12327: Fixed stack buffer overflow in the openhost() command-line call of NTPQ/NTPDC. (bsc#1098531)
  • CVE-2018-7170: Add further tweaks to improve the fix for the ephemeral association time spoofing additional protection (bsc#1083424)

Please also see https://www.nwtime.org/network-time-foundation-publishes-ntp-4-2-8p12/ for more information.

Record
SUSE-SU-2018:3386-1
Updated
2026-11-02

Affected products

Affected packages

Affected packages
PackageAffectedFixed
ntp
Debian:11
before 1:4.2.8p11+dfsg-1
1:4.2.8p11+dfsg-1
ntp
Mageia:6
before 4.2.8p11-1.mga6
4.2.8p11-1.mga6
ntp
SUSE:Linux Enterprise Server 11 SP4
before 4.2.8p11-64.4.1
4.2.8p11-64.4.1
ntp
SUSE:Linux Enterprise Server for SAP Applications 11 SP4
before 4.2.8p11-64.4.1
4.2.8p11-64.4.1
ntp
SUSE:Linux Enterprise Desktop 12 SP3
before 4.2.8p11-64.3.2
4.2.8p11-64.3.2
ntp
SUSE:Linux Enterprise Server 12 SP3
before 4.2.8p11-64.3.2
4.2.8p11-64.3.2
ntp
SUSE:Linux Enterprise Server for SAP Applications 12 SP3
before 4.2.8p11-64.3.2
4.2.8p11-64.3.2
ntp
SUSE:Linux Enterprise Server 12-LTSS
before 4.2.8p11-46.26.2
4.2.8p11-46.26.2
ntp
SUSE:OpenStack Cloud 7
before 4.2.8p11-64.5.1
4.2.8p11-64.5.1
ntp
SUSE:Linux Enterprise Desktop 12 SP3
before 4.2.8p11-64.5.1
4.2.8p11-64.5.1
Show 29 moreShow less
Affected packages
PackageAffectedFixed
ntp
SUSE:Linux Enterprise Server for SAP Applications 12 SP1
before 4.2.8p11-64.5.1
4.2.8p11-64.5.1
ntp
SUSE:Linux Enterprise Server for SAP Applications 12 SP2
before 4.2.8p11-64.5.1
4.2.8p11-64.5.1
ntp
SUSE:Linux Enterprise Server 12 SP1-LTSS
before 4.2.8p11-64.5.1
4.2.8p11-64.5.1
ntp
SUSE:Linux Enterprise Server 12 SP2-LTSS
before 4.2.8p11-64.5.1
4.2.8p11-64.5.1
ntp
SUSE:Linux Enterprise Server 12 SP3
before 4.2.8p11-64.5.1
4.2.8p11-64.5.1
ntp
SUSE:Linux Enterprise Server for SAP Applications 12 SP3
before 4.2.8p11-64.5.1
4.2.8p11-64.5.1
ntp
SUSE:Enterprise Storage 4
before 4.2.8p11-64.5.1
4.2.8p11-64.5.1
ntp
SUSE:Linux Enterprise Server 12 SP2-BCL
before 4.2.8p11-64.5.1
4.2.8p11-64.5.1
ntp
SUSE:OpenStack Cloud 7
before 4.2.8p12-64.8.2
4.2.8p12-64.8.2
ntp
SUSE:Linux Enterprise Desktop 12 SP3
before 4.2.8p12-64.8.2
4.2.8p12-64.8.2
ntp
SUSE:Linux Enterprise Server for SAP Applications 12 SP2
before 4.2.8p12-64.8.2
4.2.8p12-64.8.2
ntp
SUSE:Linux Enterprise Server 12 SP1-LTSS
before 4.2.8p12-64.8.2
4.2.8p12-64.8.2
ntp
SUSE:Linux Enterprise Server 12 SP2-LTSS
before 4.2.8p12-64.8.2
4.2.8p12-64.8.2
ntp
SUSE:Linux Enterprise Server 12 SP2-BCL
before 4.2.8p12-64.8.2
4.2.8p12-64.8.2
ntp
SUSE:Linux Enterprise Server 12 SP3
before 4.2.8p12-64.8.2
4.2.8p12-64.8.2
ntp
SUSE:Linux Enterprise Server for SAP Applications 12 SP3
before 4.2.8p12-64.8.2
4.2.8p12-64.8.2
ntp
SUSE:Enterprise Storage 4
before 4.2.8p12-64.8.2
4.2.8p12-64.8.2
ntp
SUSE:Linux Enterprise Server for SAP Applications 12 SP1
before 4.2.8p12-64.8.2
4.2.8p12-64.8.2
ntp
SUSE:Linux Enterprise Server 12-LTSS
before 4.2.8p12-46.29.2
4.2.8p12-46.29.2
ntp
SUSE:Linux Enterprise Server 11 SP4
before 4.2.8p12-64.7.1
4.2.8p12-64.7.1
ntp
SUSE:Linux Enterprise Server for SAP Applications 11 SP4
before 4.2.8p12-64.7.1
4.2.8p12-64.7.1
ntp
SUSE:Linux Enterprise Point of Sale 11 SP3
before 4.2.8p12-48.21.1
4.2.8p12-48.21.1
ntp
SUSE:Linux Enterprise Server 11 SP3-LTSS
before 4.2.8p12-48.21.1
4.2.8p12-48.21.1
ntp
SUSE:Linux Enterprise Server 11 SP3-TERADATA
before 4.2.8p12-48.21.1
4.2.8p12-48.21.1
ntp
SUSE:Linux Enterprise Module for Legacy 15
before 4.2.8p12-4.3.2
4.2.8p12-4.3.2
ntp
Ubuntu:Pro:14.04:LTS
All versions, plus listed versions
1:4.2.6.p5+dfsg-3ubuntu21:4.2.6.p5+dfsg-3ubuntu2.14.04.11:4.2.6.p5+dfsg-3ubuntu2.14.04.21:4.2.6.p5+dfsg-3ubuntu2.14.04.31:4.2.6.p5+dfsg-3ubuntu2.14.04.5
Show 8 moreShow less
1:4.2.6.p5+dfsg-3ubuntu2.14.04.61:4.2.6.p5+dfsg-3ubuntu2.14.04.71:4.2.6.p5+dfsg-3ubuntu2.14.04.81:4.2.6.p5+dfsg-3ubuntu2.14.04.101:4.2.6.p5+dfsg-3ubuntu2.14.04.111:4.2.6.p5+dfsg-3ubuntu2.14.04.121:4.2.6.p5+dfsg-3ubuntu2.14.04.131:4.2.6.p5+dfsg-3ubuntu2.14.04.13+esm1
None known
ntp
Ubuntu:16.04:LTS
All versions, plus listed versions
1:4.2.6.p5+dfsg-3ubuntu81:4.2.6.p5+dfsg-3ubuntu8.11:4.2.6.p5+dfsg-3ubuntu91:4.2.8p4+dfsg-3ubuntu11:4.2.8p4+dfsg-3ubuntu2
Show 13 moreShow less
1:4.2.8p4+dfsg-3ubuntu31:4.2.8p4+dfsg-3ubuntu41:4.2.8p4+dfsg-3ubuntu51:4.2.8p4+dfsg-3ubuntu5.11:4.2.8p4+dfsg-3ubuntu5.21:4.2.8p4+dfsg-3ubuntu5.31:4.2.8p4+dfsg-3ubuntu5.41:4.2.8p4+dfsg-3ubuntu5.51:4.2.8p4+dfsg-3ubuntu5.61:4.2.8p4+dfsg-3ubuntu5.71:4.2.8p4+dfsg-3ubuntu5.81:4.2.8p4+dfsg-3ubuntu5.91:4.2.8p4+dfsg-3ubuntu5.10
None known
ntp
Ubuntu:Pro:18.04:LTS
All versions, plus listed versions
1:4.2.8p10+dfsg-5ubuntu31:4.2.8p10+dfsg-5ubuntu41:4.2.8p10+dfsg-5ubuntu51:4.2.8p10+dfsg-5ubuntu61:4.2.8p10+dfsg-5ubuntu7
Show 7 moreShow less
1:4.2.8p10+dfsg-5ubuntu7.11:4.2.8p10+dfsg-5ubuntu7.1+esm11:4.2.8p10+dfsg-5ubuntu7.1+esm21:4.2.8p10+dfsg-5ubuntu7.21:4.2.8p10+dfsg-5ubuntu7.2+esm11:4.2.8p10+dfsg-5ubuntu7.31:4.2.8p10+dfsg-5ubuntu7.3+esm1
None known
ntp
openSUSE:Tumbleweed
before 4.2.8p15-7.2
4.2.8p15-7.2

History

History
RecordedChangedSources
aliasesEUVD
first indexedCVE List, GitHub Advisories, NVD, OSV

Dates are when Every CVE recorded each change. Upstream dates may differ.

In short

CVE-2018-7170 is a medium vulnerability (CVSS 5.3) in Ntp, published March 6, 2018. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 2.69%, the 85th percentile. Fixed in ntp 1:4.2.8p11+dfsg-1.

References

Show 54 moreShow less
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