CVE-2015-8140 Ntp CVE debrief

Who should care

Administrators and defenders who run NTP services, especially environments exposing ntpq management traffic across shared, routed, or otherwise monitorable networks. This is most relevant where packet sniffing on the path is plausible or where ntpq traffic is not tightly controlled.

Technical summary

The CVE description states that the ntpq protocol in NTP before 4.2.8p7 allows remote attackers to conduct replay attacks by sniffing the network. NVD assigns CVSS v3.0 vector AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:L and lists CWE-284. The supplied NVD CPE criteria indicate affected NTP releases in the 4.2.8 family and earlier.

Defensive priority

Medium. The issue is network-reachable and does not require authentication, but exploitation depends on the attacker being able to sniff traffic and on replay conditions, which raises attack complexity. Prioritize systems where ntpq is exposed on untrusted or broadly shared networks.

Recommended defensive actions

• Confirm whether any deployed NTP instances are older than 4.2.8p7 and update to a fixed release or vendor-supported build.
• Restrict access to ntpq and related management traffic to trusted administrative networks only.
• Reduce exposure to traffic sniffing by segmenting management networks and limiting lateral visibility.
• Review firewall and ACL rules so NTP administration endpoints are not reachable from untrusted networks.
• Use vendor and downstream advisories to verify package-specific remediation guidance for your platform.

Evidence notes

The supplied NVD record states that the ntpq protocol in NTP before 4.2.8p7 allows remote attackers to conduct replay attacks by sniffing the network. NVD also lists CVSS v3.0 AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:L and CWE-284. The record includes a vendor advisory link and multiple downstream advisories, supporting that this issue was tracked and remediated in vendor ecosystems.

Official resources