NTP BUG 3388: Buffer Overflow in DPTS Clock

Last update: November 3, 2025 16:09 UTC (9cbb45cb6)

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Summary

Resolved	4.2.8p10	21 Mar 2017
References	Bug 3388	CVE-2017-6462
Affects	All versions of NTP, up to but not including ntp-4.2.8p10, and ntp-4.3.0 up to, but not including ntp-4.3.94.	Resolved in 4.2.8p10.
CVSS2 Score	LOW 1.0	AV:L/AC:H/Au:S/C:N/I:N/A:P
CVSS3 Score	LOW 1.6	CVSS:3.0/AV:P/AC:H/PR:H/UI:R/S:U/C:N/I:N/A:L

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Description

There is a potential for a buffer overflow in the legacy Datum Programmable Time Server refclock driver. Here the packets are processed from the /dev/datum device and handled in datum_pts_receive(). Since an attacker would be required to somehow control a malicious /dev/datum device, this does not appear to be a practical attack and renders this issue “Low” in terms of severity.

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Mitigation

• If you have a Datum reference clock installed and think somebody may maliciously change the device, upgrade to 4.2.8p10 or later.
• Properly monitor your ntpd instances, and auto-restart ntpd (without -g) if it stops running.

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Credit

This weakness was discovered by Cure53.

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Timeline

• 2017 Mar 21: Public release
• 2017 Mar 06: Early Access Program Release: Premier and Partner Institutional Members
• 2017 Mar 06: Notification to Institutional Members
• 2017 Feb 09: Mozilla/Cure53 audit received