CVE-2015-7691: The crypto_xmit function in ntpd in NTP 4.2.x before 4.2.8p4, and 4.3.x before 4.3.77 allows remote attacke...

Security readout for executives and security teams

CVE-2015-7691 is a denial-of-service flaw in ntpd. A remote attacker could crash vulnerable NTP services using specially crafted packets involving Autokey operations. The main business risk is loss of time synchronization, which can affect authentication, logging, monitoring, and distributed systems. Exposure is most likely where vulnerable ntpd versions are reachable over the network, especially systems offering NTP service to untrusted networks. The source bundle does not provide CPEs, exact downstream package versions, or configuration-specific prerequisites beyond the named NTP versions and Autokey-related packet handling. Address during normal vulnerability remediation, faster for public or mission-critical NTP servers. The issue can disrupt dependent systems, but provided sources do not support active exploitation or data compromise. Mitigation focus: Upgrade ntpd to vendor-fixed packages or NTP 4.2.8p4 / 4.3.77 or later.; Review Red Hat, Debian, Gentoo, Oracle, NetApp, or relevant vendor guidance.; Limit NTP service exposure to trusted networks where operationally feasible..

Prepared

Jun 12, 2026, 21:41 UTC (UTC+00:00)

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.