CVE-2020-15025Network attack vector

Daemon crash via unreleased CMAC packet allocations

Published Jun 24, 2020 · Updated Aug 4, 2024

Memory leak in ntpd 4.2.8p11 through 4.2.8p14 and 4.3.97 through 4.3.100 allows remote authenticated users to crash the daemon. For each packet using a CMAC key ID, CMAC cleanup fails to fully remove the CMAC data structure, leaving a small allocation unreleased. Exploitation requires a configured CMAC algorithm and associated key in ntp.keys; repeated authenticated packets exhaust memory until ntpd aborts.

CVSS severity4.4
Medium
EPSS probability3.36%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Memory leak in ntpd 4.2.8p11 through 4.2.8p14 and 4.3.97 through 4.3.100 allows remote authenticated users to crash the daemon. For each packet using a CMAC key ID, CMAC cleanup fails to fully remove the CMAC data structure, leaving a small allocation unreleased. Exploitation requires a configured CMAC algorithm and associated key in ntp.keys; repeated authenticated packets exhaust memory until ntpd aborts.

The record

CVE
CVE-2020-15025
Published
Jun 24, 2020
Updated
Aug 4, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-401, T1499.003
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Jun 24, 2020CVE publishedPublication date reported by the CVE source.
  2. Aug 4, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

4.9NVDCVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H
6.3NTP ProjectAV:N/AC:M/Au:S/C:N/I:N/A:C
4.0NVDAV:N/AC:L/Au:S/C:N/I:N/A:P
4.4MITRECVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-401Missing Release of Memory after Effective Lifetime
T1499.003Application Exhaustion Flood

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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