What is CVE-2013-5211?

CVE-2013-5211 is a vulnerability in NTP, classified under Improper Input Validation. Published 2014-01-02.

Is CVE-2013-5211 known to be exploited?

34 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.

Improper input validation in NTP

CVE-2013-5211

The monlist feature in ntp_request.c in ntpd in NTP before 4.2.7p26 allows remote attackers to cause a denial of service (traffic amplification) via forged (1) REQ_MON_GETLIST or (2) REQ_MON_GETLIST_1 requests, as exploited in the wild in December 2013.

Vulnerability class: Drupalgeddon 2 (CVE-2018-7600)

Published 2014-01-02 · last modified 2026-06-16.

CVSS v2 metric

CVSS v2 base score 5.0 (Medium). Vector: AV:N/AC:L/Au:N/C:N/I:N/A:P. This CVE predates CVSS v3 and has no v3 score from NVD.

EPSS exploit prediction

EPSS: 0.975 (99.9th percentile), scored 2026-10-16.

Very high probability of exploitation in the next 30 days — among the top 0.1% most-likely-to-be-exploited CVEs. 100th percentile — 99.9% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.975 · newest: 0.975 · change: 0.000

Affected products

NTP — versions 4.2.7
Oracle Linux — versions 6, 7
openSUSE — versions 11.4

Weakness classification (CWE)

CWE-20 — Improper Input Validation

Public proof-of-concept exploits

References

secunia.com/advisories/59288 (Not Applicable, third-party-advisory)
h20564.www2.hpe.com/portal/site/hpsc/public/kb/docDisplay (Third Party Advisory)
lists.opensuse.org/opensuse-updates/2014-09/msg00031.html (vendor-advisory, Third Party Advisory)
www.oracle.com/technetwork/topics/security/linuxbulletinjul2016-3090544.html (Third Party Advisory)
marc.info/ (vendor-advisory, Mailing List)
www.us-cert.gov/ncas/alerts/TA14-013A (US Government Resource, Third Party Advisory, third-party-advisory)
www.securityfocus.com/bid/64692 (VDB Entry, Third Party Advisory, vdb-entry, Broken Link)
www.kb.cert.org/vuls/id/348126 (US Government Resource, Third Party Advisory, third-party-advisory)
marc.info/ (vendor-advisory, Mailing List, Third Party Advisory)
openwall.com/lists/oss-security/2013/12/30/6 (mailing-list, Mailing List)

Frequently asked questions

What is CVE-2013-5211?: CVE-2013-5211 is a vulnerability in NTP, classified under Improper Input Validation. Published 2014-01-02.
Is CVE-2013-5211 known to be exploited?: 34 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.