{"cve":"CVE-2009-3563","nvd":{"published":"2009-12-09T18:30:00.390","modified":"2026-06-16T23:11:54.260","status":"Modified","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_v4":null,"cvss_v3":null,"cwes":[],"references":["ftp://ftp.netbsd.org/pub/NetBSD/security/advisories/NetBSD-SA2010-005.txt.asc","http://aix.software.ibm.com/aix/efixes/security/xntpd_advisory.asc","http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=560074","http://kb.juniper.net/InfoCenter/index?page=content&id=JSA10673","http://kb.juniper.net/InfoCenter/index?page=content&id=JSA10691"],"products":["ntp:ntp"],"source":"nvd","synced_at":"2026-10-19T19:54:26.868835795+00:00"},"epss":{"cve":"CVE-2009-3563","score":0.32059,"percentile":0.98312,"date":"2026-10-31"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}