ZDF
Sign inSign up

Vulnerabilities

Threat intelligence · CVE-2016-4956

NTP.org ntpd is vulnerable to denial of service a NTP.org's reference implementation of NTP server, ntpd, contains multiple vulnerabilities.

Published Jun 8, 2016 · the affected product

Last checked Oct 31, 2026. A connected source was read within the last 7 days.

Check this week

CVE-2016-4956 is not in CISA KEV. FIRST estimates a 16.35% chance of exploitation in the next 30 days. Check whether you run the affected product.

Gaps on this record

  • No plain product name is stored. The page cannot tell you which product to check.
  • No version range is stored. A customer cannot check an installed version against this record.
  • No vendor fix or required action is stored. Compare the linked advisory before you change production.
Severity
Unknown—
Known exploitation
Not in CISA/VulnCheck KEV
EPSS
16.35%
Remediation
Not established
Affected products
See sources for product scope

NTP.org ntpd is vulnerable to denial of service a NTP.org's reference implementation of NTP server, ntpd, contains multiple vulnerabilities. A brief overview follows, but details may be found in NTP's security advisory listing and in the individual links below. CRYPTO-NAK denial of service introduced in Sec 3007 patch. See Sec 3046, CVE-2016-4957. The CVSS score below describes this vulnerability. Bad authentication

No affected version ranges are stored yet. Use the vendor advisory before you decide this record does not apply.

How to fix CVE-2016-4956

What to do

Three questions, each answered from this record only. Confirm the vendor advisory before you patch.

Should you patch?

CVE-2016-4956 is not in CISA KEV. FIRST estimates a 16.35% chance of exploitation in the next 30 days. Check whether you run the affected product.

Which versions are affected?

Affected version ranges are not on this record. Compare the installed version with the linked vendor advisory before you change production.

What should an analyst verify?

No weakness class is stored. EPSS 16.35%. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.

Code

The project this record applies to. Exploit listings stay in References.

No public source repository is identified for this product.

Timeline

Detection, updates, and resolution for this record.

  1. Jun 8, 2016 · AlienVault OTX

    Detected

    NTP.org ntpd is vulnerable to denial of service a NTP.org's reference implementation of NTP server, ntpd, contains multiple vulnerabilities. A brief overview follows, but details may be found in NTP's security advisory listing and in the individual links below. CRYPTO-NAK denial of service introduced in Sec 3007 patch. See Sec 3046, CVE-2016-4957. The CVSS score below describes this vulnerability.

Sources

References

Freshness

Last verified in this catalog Oct 31, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.

  • FIRST EPSSOct 31, 2026
  • AlienVault OTXOct 31, 2026