CVE-2021-27663Network attack vector

Unauthenticated system access via inadequate API authorization

Published Aug 30, 2021 · Updated Sep 17, 2024

Improper authorization in Johnson Controls AC2000 10.1 through 10.5 allows remote attackers to access protected system functionality. The AC2000 API does not adequately verify a provable user identity before allowing protected functionality, but the affected endpoint and check are undisclosed. No credentials or user interaction are required, but only deployments with SSO and the AC2000 API installed are affected.

CVSS severity8.2
High
EPSS probability1.67%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper authorization in Johnson Controls AC2000 10.1 through 10.5 allows remote attackers to access protected system functionality. The AC2000 API does not adequately verify a provable user identity before allowing protected functionality, but the affected endpoint and check are undisclosed. No credentials or user interaction are required, but only deployments with SSO and the AC2000 API installed are affected.

The record

CVE
CVE-2021-27663
Published
Aug 30, 2021
Updated
Sep 17, 2024
Vendor
Johnson Controls
Product
AC2000
Classifications
CWE-285, T1210
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 30, 2021CVE publishedPublication date reported by the CVE source.
  2. Sep 17, 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=10.1 <=10.5

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Johnson Controls · AC2000version=10.1 <=10.5

Published CVSS scores

9.8NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
9.3NIST NVDAV:N/AC:M/Au:N/C:C/I:C/A:C
8.2Johnson ControlsCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N

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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

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
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-285Improper Authorization
T1210Exploitation of Remote Services

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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