Vulnerability Monitor

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CVE-2018-8956

ntpd in ntp 4.2.8p10, 4.2.8p11, 4.2.8p12 and 4.2.8p13 allow remote attackers to prevent a broadcast client from synchronizing its clock with a broadcast NTP server via soofed mode 3 and mode 5 packets. The attacker must either be a part of the same broadcast network or control a slave in that broadcast network that can capture certain required packets on the attacker's behalf and send them to the attacker.

Security Impact Summary

This vulnerability carries a MEDIUM severity rating with a CVSS v3.1 score of 5.3, indicating it can be exploited remotely over the network with relatively low complexity without requiring user interaction and does not require pre-existing privileges . The vulnerability impacts and limited availability for affected systems. Impacting 1 product from ntp organizations running these solutions should prioritize assessment and patching.

Historical Context

Reported in 2020, this vulnerability emerged during an era marked by increased sophistication in supply chain attacks, cloud infrastructure vulnerabilities, and software-as-a-service (SaaS) security challenges. Security practices during this period emphasized zero-trust architectures, container security, and API protection.

Published

2020-05-06T19:15:12.410

Last Modified

2026-06-17T02:05:43.317

Status

Modified

Source

[email protected]

Severity

CVSSv3.1: 5.3 (MEDIUM)

CVSSv2 Vector

AV:N/AC:L/Au:N/C:N/I:N/A:P

Access Vector: NETWORK
Access Complexity: LOW
Authentication: NONE
Confidentiality Impact: NONE
Integrity Impact: NONE
Availability Impact: PARTIAL

Exploitability Score

10.0

Impact Score

2.9

Weaknesses

Type: Primary
CWE-20

Affected Vendors & Products

Type	Vendor	Product	Version/Range	Vulnerable?
Application	ntp	ntp	4.2.8	Yes
Application	ntp	ntp	4.2.8	Yes
Application	ntp	ntp	4.2.8	Yes
Application	ntp	ntp	4.2.8	Yes

References

http://lists.opensuse.org/opensuse-security-announce/2020-07/msg00005.html ([email protected])
http://lists.opensuse.org/opensuse-security-announce/2020-07/msg00044.html ([email protected])
http://www.ntp.org/ Vendor Advisory ([email protected])
https://arxiv.org/abs/2005.01783 Third Party Advisory ([email protected])
https://nikhiltripathi.in/NTP_attack.pdf Third Party Advisory ([email protected])
https://security.netapp.com/advisory/ntap-20200518-0006/ ([email protected])
https://tools.ietf.org/html/rfc5905 Third Party Advisory ([email protected])
http://lists.opensuse.org/opensuse-security-announce/2020-07/msg00005.html (af854a3a-2127-422b-91ae-364da2661108)
http://lists.opensuse.org/opensuse-security-announce/2020-07/msg00044.html (af854a3a-2127-422b-91ae-364da2661108)
http://www.ntp.org/ Vendor Advisory (af854a3a-2127-422b-91ae-364da2661108)
https://arxiv.org/abs/2005.01783 Third Party Advisory (af854a3a-2127-422b-91ae-364da2661108)
https://nikhiltripathi.in/NTP_attack.pdf Third Party Advisory (af854a3a-2127-422b-91ae-364da2661108)
https://security.netapp.com/advisory/ntap-20200518-0006/ (af854a3a-2127-422b-91ae-364da2661108)
https://tools.ietf.org/html/rfc5905 Third Party Advisory (af854a3a-2127-422b-91ae-364da2661108)

How SecUtils Interprets This CVE

SecUtils normalizes and enriches National Vulnerability Database (NVD) records by standardizing vendor and product identifiers, aggregating vulnerability metadata from both NVD and MITRE sources, and providing structured context for security teams. For ntp's affected products, we extract Common Platform Enumeration (CPE) data, Common Weakness Enumeration (CWE) classifications, CVSS severity metrics, and reference data to enable rapid vulnerability prioritization and asset correlation. This record contains no exploit code, proof-of-concept instructions, or attack methodologies—only defensive intelligence necessary for patch management, risk assessment, and security operations.