CVE-2015-7855: The decodenetnum function in ntpd in NTP 4.2.x before 4.2.8p4, and 4.3.x before 4.3.77 allows remote attack...

Security readout for executives and security teams

CVE-2015-7855 is a remote denial-of-service flaw in ntpd. A specially crafted NTP control packet with an overly long value can trigger an assertion failure and stop time service. It does not indicate data theft or code execution, but disrupted time synchronization can affect authentication, logging, monitoring, and operational reliability. Exposure is most likely where affected ntpd versions run on servers, network appliances, or industrial systems and NTP control/query traffic can reach them. Vendor advisories from Debian, Gentoo, Red Hat, HPE, NetApp, and Siemens suggest this may appear through operating systems and embedded product stacks. Treat this as a reliability and operational resilience issue. It is not evidenced as actively exploited here, but time service outages can cascade into logging, authentication, and incident response problems. Patch exposed and business-critical NTP services during the next practical maintenance window. Mitigation focus: Upgrade NTP to 4.2.8p4, 4.3.77, or later fixed releases.; Apply relevant vendor security updates for packaged or embedded ntpd.; Check vendor advisories for supported configuration-level mitigations..

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.