Rapid7

vulnerability

Arch Linux: Denial of service (CVE-2016-7426)

Severity
4
CVSS
(AV:N/AC:M/Au:N/C:N/I:N/A:P)
Published
Jan 13, 2017
Added
Jul 11, 2025
Modified
Mar 25, 2026

Description

When ntpd is configured with rate limiting for all associations (restrict default limited in ntp.conf), the limits are applied also to responses received from its configured sources. An attacker who knows the sources (e.g., from an IPv4 refid in server response) and knows the system is (mis)configured in this way can periodically send packets with spoofed source address to keep the rate limiting activated and prevent ntpd from accepting valid responses from its sources.

Solution

arch-linux-upgrade-latest

References

    Title
    Rapid7 Labs

    2026 Global Threat Landscape Report

    The predictive window has collapsed. Exploitation follows disclosure in days. See how attackers are accelerating and how to stay ahead.