CVE-2015-1799

Severity: medium (CVSS 4.3 v2.0)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.9% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2015-04-08 · updated 2026-06-17
Weakness: CWE-17

Description

The symmetric-key feature in the receive function in ntp_proto.c in ntpd in NTP 3.x and 4.x before 4.2.8p2 performs state-variable updates upon receiving certain invalid packets, which makes it easier for man-in-the-middle attackers to cause a denial of service (synchronization loss) by spoofing the source IP address of a peer.

Affected products

NTP: through 4.2.7p444

References

http://bugs.ntp.org/show_bug.cgi?id=2781
http://listengine.tuxfamily.org/chrony.tuxfamily.org/chrony-announce/2015/04/msg00002.html
http://lists.apple.com/archives/security-announce/2015/Jun/msg00002.html
http://lists.fedoraproject.org/pipermail/package-announce/2015-April/155863.html
http://lists.fedoraproject.org/pipermail/package-announce/2015-April/155864.html
http://lists.opensuse.org/opensuse-updates/2015-04/msg00052.html
http://marc.info/?l=bugtraq&m=143213867103400&w=2
http://marc.info/?l=bugtraq&m=145750740530849&w=2
http://rhn.redhat.com/errata/RHSA-2015-1459.html
http://support.apple.com/kb/HT204942
http://support.ntp.org/bin/view/Main/SecurityNotice#Recent_Vulnerabilities
http://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20150408-ntpd

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