CVE-2016-4955

MEDIUMCVSS 5.9/10EPSS 8.80%

Last modified

CVE-2016-4955 is a medium-severity vulnerability rated 5.9/10 on the CVSS scale. ntpd in NTP 4.x before 4.2.8p8, when autokey is enabled, allows remote attackers to cause a denial of service (peer-variable clearing and association outage) by sending (1) a spoofed crypto-NAK packet or (2) a packet with an incorrect MAC value at a certain time.. EPSS estimates a 8.80% chance of exploitation in the next 30 days.

Description

ntpd in NTP 4.x before 4.2.8p8, when autokey is enabled, allows remote attackers to cause a denial of service (peer-variable clearing and association outage) by sending (1) a spoofed crypto-NAK packet or (2) a packet with an incorrect MAC value at a certain time.

Metrics

CVSS 3.1
5.9/10

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H

EPSS Probability
8.80%

94.5th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

VendorProductVersionsUpdate
NtpNtp>= 4.2.0, < 4.2.8
NtpNtp>= 4.3.0, < 4.3.93
NtpNtp4.2.8
OracleSolaris10
OracleSolaris11.3
SuseManager Proxy2.1
SuseOpenstack Cloud5
NovellSuse Manager2.1
OpensuseLeap42.1
OpensuseOpensuse13.2
SuseLinux Enterprise Desktop12Sp1
SuseLinux Enterprise Server11Sp2
SuseLinux Enterprise Server12Sp1
SiemensSimatic Net Cp 443-1 Opc Ua FirmwareAll versions

References

Timeline

Published
Last Modified
Status
Modified

Frequently Asked Questions

What is CVE-2016-4955?
ntpd in NTP 4.x before 4.2.8p8, when autokey is enabled, allows remote attackers to cause a denial of service (peer-variable clearing and association outage) by sending (1) a spoofed crypto-NAK packet or (2) a packet with an incorrect MAC value at a certain time.
How severe is CVE-2016-4955?
CVE-2016-4955 has a CVSS score of 5.9/10 (MEDIUM severity). The EPSS model estimates a 8.80% probability of exploitation in the next 30 days.
How do I fix CVE-2016-4955?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2016-4955?

Run a free Strix scan to check your systems for this vulnerability.

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Source: NVD / NIST