CVE-2020-28466Network attack vector

Server crash via cyclic service imports

Published Mar 7, 2021 · Updated Sep 16, 2024

Denial of service in NATS.io NATS Server 2.0.0 through 2.1.9 allows remote authenticated users to crash the server via cyclic service imports. The AddServiceImportWithClaim path accepted an import without checking overlapping exports and reverse imports, so a cycle repeatedly consumed CPU and memory. Exploitation requires control of at least two accounts on a service exposed to untrusted account holders and kills the server after resource exhaustion.

CVSS severity7.5
High
EPSS probability3.73%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Denial of service in NATS.io NATS Server 2.0.0 through 2.1.9 allows remote authenticated users to crash the server via cyclic service imports. The AddServiceImportWithClaim path accepted an import without checking overlapping exports and reverse imports, so a cycle repeatedly consumed CPU and memory. Exploitation requires control of at least two accounts on a service exposed to untrusted account holders and kills the server after resource exhaustion.

The record

CVE
CVE-2020-28466
Published
Mar 7, 2021
Updated
Sep 16, 2024
Vendor
NATS.io
Product
NATS Server
Classifications
CWE-400, T1499.004
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Mar 7, 2021CVE publishedPublication date reported by the CVE source.
  2. Sep 16, 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?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0 <unspecified

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

NATS.io · NATS Serverversion=0 <unspecified

Published CVSS scores

7.5GitHub Advisory DatabaseCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
5.0NVDAV:N/AC:L/Au:N/C:N/I:N/A:P

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-400Uncontrolled Resource Consumption
T1499.004Application or System Exploitation

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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