PT-2016-4856 · Ntpsec+7 · Ntpsec+7
Jonathan Gardner
+1
·
Published
2016-04-28
·
Updated
2025-04-20
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CVE-2016-1548
CVSS v3.1
7.2
High
| Vector | AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:L |
Name of the Vulnerable Software and Affected Versions
NTP versions 4.2.8p4 and earlier
NTPSec version aa48d001683e5b791a743ec9c575aaf7d867a2b0c
Description
An attacker can spoof a packet from a legitimate ntpd server with an origin timestamp that matches the
peer->dst timestamp recorded for that server. This allows the attacker to change the time of an ntpd client or deny service to an ntpd client by forcing it to change from basic client/server mode to interleaved symmetric mode. After making this switch, the client will reject all future legitimate server responses. It is possible to force the victim client to move time after the mode has been changed.Recommendations
For NTP versions 4.2.8p4 and earlier, consider updating to a newer version to mitigate the risk.
For NTPSec version aa48d001683e5b791a743ec9c575aaf7d867a2b0c, consider updating to a newer version to mitigate the risk.
As a temporary workaround, consider restricting access to the
ntpd server to minimize the risk of exploitation.Exploit
Fix
DoS
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Weakness Enumeration
Related Identifiers
Affected Products
Centos
Cisco Nexus
Freebsd
Ntp
Ntpsec
Red Hat
Suse
Ubuntu