Vulnerability identifier: #VU87727

Vulnerability risk: Medium

CVSSv3.1: 7 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:F/RL:O/RC:C]

CVE-ID: CVE-2009-3563

CWE-ID: CWE-399

Exploitation vector: Network

Exploit availability: Yes

Vulnerable software:
ntp
Server applications / Other server solutions

Vendor:

Description

The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.

The vulnerability exists due to improper management of internal resources in ntp_request.c. A remote attacker can perform a denial of service (DoS) attack using the MODE_PRIVATE to send a spoofed request or response packets that trigger a continuous exchange of MODE_PRIVATE error responses between two NTP daemons.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

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External links
http://rhn.redhat.com/errata/RHSA-2009-1651.html
http://www.kb.cert.org/vuls/id/MAPG-7X7VD7
http://www.debian.org/security/2009/dsa-1948
http://support.ntp.org/bin/view/Main/SecurityNotice#DoS_attack_from_certain_NTP_mode
http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=560074
http://rhn.redhat.com/errata/RHSA-2009-1648.html
http://lists.ntp.org/pipermail/announce/2009-December/000086.html
http://www.kb.cert.org/vuls/id/568372
http://security-tracker.debian.org/tracker/CVE-2009-3563
http://support.ntp.org/bugs/show_bug.cgi?id=1331
http://www.kb.cert.org/vuls/id/MAPG-7X7V6J
http://bugzilla.redhat.com/show_bug.cgi?id=531213
http://www.redhat.com/archives/fedora-package-announce/2009-December/msg00809.html
http://www.redhat.com/archives/fedora-package-announce/2009-December/msg00763.html
http://rhn.redhat.com/errata/RHSA-2010-0095.html
http://support.avaya.com/css/P8/documents/100071808
http://www-01.ibm.com/support/docview.wss?uid=isg1IZ71047
http://aix.software.ibm.com/aix/efixes/security/xntpd_advisory.asc
http://www-01.ibm.com/support/docview.wss?uid=isg1IZ68659
http://lists.vmware.com/pipermail/security-announce/2010/000082.html
ftp://ftp.netbsd.org/pub/NetBSD/security/advisories/NetBSD-SA2010-005.txt.asc
http://secunia.com/advisories/39593
http://www.vupen.com/english/advisories/2010/0993
http://sunsolve.sun.com/search/document.do?assetkey=1-77-1021781.1-1
http://marc.info/?l=bugtraq&m=136482797910018&w=2
http://marc.info/?l=bugtraq&m=130168580504508&w=2
http://kb.juniper.net/InfoCenter/index?page=content&id=JSA10691
http://kb.juniper.net/InfoCenter/index?page=content&id=JSA10673
http://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A7076
http://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A19376
http://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A12141
http://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A11225
http://www.kb.cert.org/vuls/id/417980

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Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability. However, a fully functional exploit for this vulnerability is available.