CVE-2009-3563
MEDIUM · CVSS 6.4EPSS 32.1%EU EUVD
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.
Key facts
- CVSS score
- 6.4 (v2.0)
- Severity
- MEDIUM
- CVSS vector
AV:N/AC:L/Au:N/C:N/I:P/A:P- EPSS score
- 32.1% (98th percentile)
- In CISA KEV
- No
- In EU EUVD
- Yes (EUVD-2009-3544)
- Published
- December 9, 2009
- NVD last modified
- June 16, 2026
- Status
- Modified
EU Vulnerability Database (EUVD)
This vulnerability is also tracked by ENISA as EUVD-2009-3544 in the EU Vulnerability Database. Last updated in EUVD on August 7, 2024.
View on the EU Vulnerability DatabaseAffected products
- ntp / ntp
- ntp / ntp
- ntp / ntp
- ntp / ntp
- ntp / ntp
- ntp / ntp
- ntp / ntp
- ntp / ntp
- ntp / ntp
- ntp / ntp
- ntp / ntp
- ntp / ntp
- ntp / ntp
- ntp / ntp
- ntp / ntp
- ntp / ntp
- ntp / ntp
- ntp / ntp
- ntp / ntp
- ntp / ntp
- ntp / ntp
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
- http://lists.vmware.com/pipermail/security-announce/2010/000082.html
- http://marc.info/?l=bugtraq&m=130168580504508&w=2
- http://marc.info/?l=bugtraq&m=136482797910018&w=2
- http://secunia.com/advisories/37629
- http://secunia.com/advisories/37922
- http://secunia.com/advisories/38764
- http://secunia.com/advisories/38794
- http://secunia.com/advisories/38832
- http://secunia.com/advisories/38834
- http://secunia.com/advisories/39593
- http://security-tracker.debian.org/tracker/CVE-2009-3563
- http://securitytracker.com/id?1023298
- http://sunsolve.sun.com/search/document.do?assetkey=1-77-1021781.1-1
- http://support.avaya.com/css/P8/documents/100071808
- http://support.ntp.org/bin/view/Main/SecurityNotice#DoS_attack_from_certain_NTP_mode(Patch)
- http://www-01.ibm.com/support/docview.wss?uid=isg1IZ68659
- http://www-01.ibm.com/support/docview.wss?uid=isg1IZ71047
- http://www.debian.org/security/2009/dsa-1948(Patch)
- http://www.kb.cert.org/vuls/id/568372(Patch, US Government Resource)
- http://www.kb.cert.org/vuls/id/MAPG-7X7V6J
- http://www.kb.cert.org/vuls/id/MAPG-7X7VD7
- http://www.securityfocus.com/bid/37255(Patch)
- http://www.vupen.com/english/advisories/2010/0510
- http://www.vupen.com/english/advisories/2010/0528
- http://www.vupen.com/english/advisories/2010/0993
- https://bugzilla.redhat.com/show_bug.cgi?id=531213
- https://lists.ntp.org/pipermail/announce/2009-December/000086.html
- https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A11225
- https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A12141
- https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A19376
- https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A7076
- https://rhn.redhat.com/errata/RHSA-2009-1648.html
- https://rhn.redhat.com/errata/RHSA-2009-1651.html
- https://rhn.redhat.com/errata/RHSA-2010-0095.html
- https://support.ntp.org/bugs/show_bug.cgi?id=1331
Last updated September 17, 2026 · Source: NVD, CISA KEV, FIRST.org EPSS
Query CVEs from your AI assistant
The CVE/NVD Explorer brain answers CVE questions directly inside Claude, ChatGPT, or any MCP assistant — always up to date, no setup. Add it once and stop pasting advisories into chat.
Add the CVE brain