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PatchSiren cyber security CVE debrief

CVE-2016-7429 Ntp CVE debrief

CVE-2016-7429 is a low-severity NTP vulnerability that can disrupt communication with a time source. According to the CVE record, versions before 4.2.8p9 may change peer state based on the interface that receives a response, which can allow a remote attacker to interfere with synchronization by sending a response to the wrong interface.

Vendor
Ntp
Product
Unknown
CVSS
LOW 3.7
CISA KEV
Not listed in stored evidence
Original CVE published
2017-01-13
Original CVE updated
2026-05-13
Advisory published
2017-01-13
Advisory updated
2026-05-13

Who should care

Organizations running affected NTP releases, especially systems that rely on NTP for time synchronization and expose reachable network paths where spoofed or misrouted responses could be delivered.

Technical summary

The NVD description says NTP before 4.2.8p9 may change the peer structure to the interface that receives a response from a source. If a response for a source is sent to an interface that the source does not use, the peer can be re-associated in a way that prevents communication with that source. NVD classifies the impact as availability-only (CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L) and maps the issue to CWE-18.

Defensive priority

Moderate for fleets that depend on NTP correctness, even though the CVSS score is low. Time synchronization problems can have knock-on effects for authentication, logging, scheduling, and distributed systems, so affected versions should be updated promptly.

Recommended defensive actions

  • Upgrade NTP to 4.2.8p9 or a later vendor-supported release that includes the fix.
  • Review vendor advisories and downstream package errata for your platform before maintenance windows.
  • Confirm which systems run affected NTP packages or embedded NTP components and prioritize externally reachable hosts first.
  • Monitor for unusual NTP behavior or unexpected loss of communication with configured time sources after remediation.
  • Use the official NTP security notice and release notes as the primary remediation references for this CVE.

Evidence notes

This debrief is based on the supplied NVD/CVE record, which lists the vulnerability description, affected version boundary, CVSS vector, CWE mapping, and official/vendor references. The CVE record was published on 2017-01-13 and later modified on 2026-05-13. The referenced NTP release notes and NTP bug/security notice are the most relevant vendor sources in the provided corpus.

Sources and references

Verified primary and authoritative sources

  • CVE-2016-7429 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2016-7429

    CVE Program - Official CVE Program record with source-provided CVE metadata.

  • CVE-2016-7429 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2016-7429

    NIST National Vulnerability Database - Official NIST NVD detail page and source-specific vulnerability assessment.

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.