CVE-2013-5211

Severity: medium (CVSS 5.0 v2.0)
Exploited in the wild: not listed in CISA KEV
EPSS: 97.5% probability of exploitation in the next 30 days
Public exploit or detection template: yes
Published: 2014-01-02 · updated 2026-06-16
Weakness: CWE-20

Description

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.

Affected products

NTP: before 4.2.7; 4.2.7, 4.2.7-p0, 4.2.7-p1, 4.2.7-p10, 4.2.7-p11, 4.2.7-p12 (+21) — fixed in 4.2.7
Opensuse: 11.4
Oracle Corporation Oracle Linux: 6, 7

How to fix

Upgrade to a fixed version: NTP 4.2.7. Check the vendor advisory for mitigations.

References

http://aix.software.ibm.com/aix/efixes/security/ntp_advisory.asc
http://bugs.ntp.org/show_bug.cgi?id=1532
http://ics-cert.us-cert.gov/advisories/ICSA-14-051-04
http://lists.ntp.org/pipermail/pool/2011-December/005616.html
http://lists.opensuse.org/opensuse-updates/2014-09/msg00031.html
http://marc.info/?l=bugtraq&m=138971294629419&w=2
http://marc.info/?l=bugtraq&m=144182594518755&w=2
http://openwall.com/lists/oss-security/2013/12/30/6
http://openwall.com/lists/oss-security/2013/12/30/7
http://secunia.com/advisories/59288
http://secunia.com/advisories/59726
http://www-947.ibm.com/support/entry/portal/docdisplay?lndocid=MIGR-5095861

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