CVE & CISA-KEV Catalog

CVE-2009-3563

MEDIUMEPSS 98th pctl
6.4
CVSS v2
NVD

Description

ntp_request.c in ntpd in NTP before 4.2.4p8, and 4.2.5, allows remote attackers to cause a denial of service (CPU and bandwidth consumption) by using MODE_PRIVATE to send a spoofed (1) request or (2) response packet that triggers a continuous exchange of MODE_PRIVATE error responses between two NTP daemons.

CVSS v2 Vector

No CVSS vector data available.

Exploit Intelligence

32.29%probability of exploitation in 30 days
98thpercentile

Very high risk: more likely to be exploited than 98% of all known CVEs.

References

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This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2026-04-23.