CVE-2017-6451

What it is

The mx4200_send function in the legacy MX4200 refclock in NTP before 4.2.8p10 and 4.3.x before 4.3.94 does not properly handle the return value of the snprintf function, which allows local users to execute arbitrary code via unspecified vectors, which trigger an out-of-bounds memory write.

At a glance

Exploitability

Can be exploited locally on the machine with a low-privilege account. High risk of data exposure, data tampering, service disruption.

Exploit odds

0.5% chance of exploitation in the next 30 days (EPSS).

Fix

A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

1. 2017-03-27 17:59 UTC PublishedDisclosed publicly on CVE.org and NVD
2. 2026-06-17 01:22 UTC Last updatedMost recent change to the record

Why it ranks here

• Exploited in the wild: no, CISA does not list it.
• Exploit odds: 0.5% in the next 30 days (EPSS).
• Severity: 7.8 HIGH (CVSS).
• Fix: a patch or advisory is linked.

Details

Published

2017-03-27 17:59 UTC

Last modified

2026-06-17 01:22 UTC

Exploit probability

0.5% · EPSS, next 30 days

Weakness

CWE-787 · Out-of-bounds write

Record status

Modified

Affected

• Ntp 4.2.8
• Ntp 4.3.0
• Ntp 4.3.1
• Ntp 4.3.2
• Ntp 4.3.3
• Ntp 4.3.4
• Ntp 4.3.5
• Ntp 4.3.6

Attack profile CVSS 3.0 · 7.8

Attack vector

Local

Complexity

Low

Privileges needed

Low

User interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Is it in your code?

Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.

Read https://cve-list.com/agent/cve/CVE-2017-6451.md and follow it. Check whether this project is affected by CVE-2017-6451. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.

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