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Vulnerability Assessment

Weakness
CWE
CWE-476
OWASP Top 10:2025
A10:2025 - Mishandling of Exceptional Conditions
ASVS 5.0
V16 - Security Logging and Error Handling Null pointer safety, defensive checks
MITRE ATT&CK

1 technique across 1 tactic: Impact

The technique list with ATT&CK links and the kill-chain view is part of the Basic plan and up.

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Impact

CVSS score of 7.5 (HIGH). Attack characteristics: network attack vector, low complexity, no privileges required, no user interaction not required. EPSS exploitation probability: 59.07%.
Exploit ScenarioDerived

A remote attacker could crash the application by dereferencing a null pointer by sending crafted requests to the affected application. No authentication is required to exploit this vulnerability.
Act Now Prioritize within 24-48h. Why: HIGH severity + EPSS > 10%.
Patch available 59.1% exploitation probability (EPSS)

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AnalysisAI

ntpd in NTP before 4.2.8p8 allows remote attackers to cause a denial of service (daemon crash) via a crypto-NAK packet. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Epss exploitation probability 59.1%.

RemediationAI

A vendor patch is available. Apply the latest security update as soon as possible. Check pointers before dereferencing. Use static analysis tools to detect null pointer paths.

Affects your stack

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Technical ContextAI · show details

This vulnerability is classified as NULL Pointer Dereference (CWE-476), which allows attackers to crash the application by dereferencing a null pointer. ntpd in NTP before 4.2.8p8 allows remote attackers to cause a denial of service (daemon crash) via a crypto-NAK packet. NOTE: this vulnerability exists because of an incorrect fix for CVE-2016-1547. Affected products include: Ntp, Oracle Solaris, Suse Manager Proxy, Suse Openstack Cloud, Novell Suse Manager. Version information: before 4.2.8.

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  • Exploit and PoC references, threat intelligence from 22 sources
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Severity by source

NVD PRIMARY 7.5 HIGH
AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Primary rating from NVD · only source for this CVE.

CVSS VectorNVD

Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

DescriptionCVE.org

ntpd in NTP before 4.2.8p8 allows remote attackers to cause a denial of service (daemon crash) via a crypto-NAK packet. NOTE: this vulnerability exists because of an incorrect fix for CVE-2016-1547.

Threat Intelligence Overview

EPSS Score
59.1%
Top 2% exploitable
Data Quality
3 sources
Confidence: Low
NVD CVE.org EPSS

How this decision was reached

The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.

SignalValue
Severity HIGH
CISA KEV No
Public POC No
EPSS 59.1%
Patch available Yes
Active threat No
Deciding rule
HIGH severity + EPSS > 10%
What every action level means
Emergency Immediate action required. Criteria: CRITICAL + in CISA KEV (actively exploited) without patch, OR CRITICAL + EPSS > 30% without patch, OR CRITICAL + active threat signals without patch.
Act Now Prioritize within 24-48h. Criteria: in KEV with patch available, OR CRITICAL + public POC, OR HIGH + EPSS > 10%, OR CRITICAL + active threat, OR any CRITICAL severity.
This Week Schedule remediation this week. Criteria: HIGH severity (CVSS 7.0-8.9). Patch within normal change window.
This Month Plan within 30 days. Criteria: MEDIUM severity (CVSS 4.0-6.9), lower exploitation probability. Include in regular patch cycle.
Monitor Track and reassess. Criteria: LOW severity (CVSS 0.1-3.9), minimal exploitation risk. No immediate action needed.

SSVC AssessmentENISA

SSVC Decision· derived
Scheduled
Exploitation· derived
None
System Exposure· derived
Open
Automatable· derived
Yes
Human Impact· derived
Medium

Priority Score

97
Low Medium High Critical
KEV: 0
EPSS: +59
CVSS: +38
PoC: 0
Weaponized: 0
Threat intel: 0
Gov advisory: 0

Attack Technique

Null Pointer Dereference MEDIUM

A null pointer dereference occurs when a program attempts to access memory through a pointer that has been set to NULL (address 0x0).

Denial of Service MEDIUM

Denial of Service attacks render applications or systems unavailable by overwhelming resources or triggering failure conditions.

Affected Products (CPE)CVE.org

cpe:2.3:a:ntp:ntp:4.2.8:p7:*:*:*:*:*:*
cpe:2.3:a:ntp:ntp:4.3.92:*:*:*:*:*:*:*
cpe:2.3:o:oracle:solaris:10:*:*:*:*:*:*:*
cpe:2.3:o:oracle:solaris:11.3:*:*:*:*:*:*:*
cpe:2.3:a:suse:manager_proxy:2.1:*:*:*:*:*:*:*
cpe:2.3:a:suse:openstack_cloud:5:*:*:*:*:*:*:*
cpe:2.3:o:novell:suse_manager:2.1:*:*:*:*:*:*:*
cpe:2.3:o:opensuse:leap:42.1:*:*:*:*:*:*:*
cpe:2.3:o:opensuse:opensuse:13.2:*:*:*:*:*:*:*
cpe:2.3:o:suse:linux_enterprise_desktop:12:sp1:*:*:*:*:*:*
cpe:2.3:o:suse:linux_enterprise_server:11:sp2:*:*:ltss:*:*:*
cpe:2.3:o:suse:linux_enterprise_server:11:sp3:*:*:ltss:*:*:*
cpe:2.3:o:suse:linux_enterprise_server:11:sp4:*:*:*:*:*:*
cpe:2.3:o:suse:linux_enterprise_server:12:sp1:*:*:*:*:*:*

More in Ntp

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CVE-2015-7871 CRITICAL POC
9.8 Aug 07

Crypto-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 authen
CVE-2013-5211 MEDIUM POC
5.0 Jan 02

The monlist feature in ntp_request.c in ntpd in NTP before 4.2.7p26 allows remote attackers to cause a denial of service
CVE-2016-7434 HIGH POC
7.5 Jan 13

The read_mru_list function in NTP before 4.2.8p9 allows remote attackers to cause a denial of service (crash) via a craf
CVE-2015-7855 MEDIUM POC
6.5 Aug 07

The decodenetnum function in ntpd in NTP 4.2.x before 4.2.8p4, and 4.3.x before 4.3.77 allows remote attackers to cause

CVE-2014-9295 HIGH POC
7.5 Dec 20

Multiple stack-based buffer overflows in ntpd in NTP before 4.2.8 allow remote attackers to execute arbitrary code via a
CVE-2014-9294 HIGH POC
7.5 Dec 20

util/ntp-keygen.c in ntp-keygen in NTP before 4.2.7p230 uses a weak RNG seed, which makes it easier for remote attackers
CVE-2014-9293 HIGH POC
7.5 Dec 20

The config_auth function in ntpd in NTP before 4.2.7p11, when an auth key is not configured, improperly generates a key,
CVE-2015-7853 CRITICAL
9.8 Aug 07

The datalen parameter in the refclock driver in NTP 4.2.x before 4.2.8p4, and 4.3.x before 4.3.77 allows remote attacker
CVE-2015-7978 HIGH
7.5 Jan 30

NTP before 4.2.8p6 and 4.3.0 before 4.3.90 allows a remote attackers to cause a denial of service (stack exhaustion) via
CVE-2015-7705 CRITICAL
9.8 Aug 07

The rate limiting feature in NTP 4.x before 4.2.8p4 and 4.3.x before 4.3.77 allows remote attackers to have unspecified

CVE-2015-5300 HIGH
7.5 Jul 21

The panic_gate check in NTP before 4.2.8p5 is only re-enabled after the first change to the system clock that was greate
CVE-2014-9296 MEDIUM POC
5.0 Dec 20

The receive function in ntp_proto.c in ntpd in NTP before 4.2.8 continues to execute after detecting a certain authentic

Same weakness CWE-476 – NULL Pointer Dereference

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CVE-2016-0742 HIGH
7.5
CVE-2014-3470 MEDIUM
4.3
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9.8
CVE-2021-3449 MEDIUM
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CVE-2015-3194 HIGH
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CVE-2026-21525 MEDIUM
6.2

Same technique Denial Of Service

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CVE-2015-5119 CRITICAL POC
9.8
CVE-2011-2462 CRITICAL POC
9.8
CVE-2011-0611 HIGH POC
8.8
CVE-2012-1889 HIGH POC
8.8
CVE-2012-0507 CRITICAL POC
9.8
CVE-2014-1761 HIGH POC
7.8
CVE-2015-5122 CRITICAL POC
9.8
CVE-2011-0609 HIGH POC
7.8

References

Advisories & patches
PATCH http://support.ntp.org/bin/view/Main/NtpBug3046 ADVISORY http://bugs.ntp.org/3046 ADVISORY http://support.ntp.org/bin/view/Main/SecurityNotice REF http://lists.opensuse.org/opensuse-security-announce/2016-06/msg00018.html REF http://lists.opensuse.org/opensuse-security-announce/2016-06/msg00023.html REF http://lists.opensuse.org/opensuse-security-announce/2016-06/msg00024.html REF http://lists.opensuse.org/opensuse-security-announce/2016-06/msg00028.html REF http://lists.opensuse.org/opensuse-security-announce/2016-06/msg00040.html REF http://www.kb.cert.org/vuls/id/321640 REF http://www.oracle.com/technetwork/topics/security/bulletinapr2016-2952098.html REF http://www.securitytracker.com/id/1036037 REF https://security.FreeBSD.org/advisories/FreeBSD-SA-16:24.ntp.asc REF https://security.gentoo.org/glsa/201607-15

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