CVE-2021-27657

mediumpriority · track · 35EPSS 0.012 · 69 %ileEUUS
grimoire priorityP3 · Track
Exploitable?
—
no known exploitation
Likely / severe?
1.24% (69th) EPSS
CVSS 6.5 · medium
Is it mine?
4 products
Check your exposure
Who says so?
4 sources
cnnvd · enisa_euvd · cisa_csaf_ot · nvd

EPSS · scored 2026-10-28

Successful exploitation of this vulnerability could give an authenticated Metasys user an unintended level of access to the server file system, allowing them to access or modify system files by sending specifically crafted web messages to the Metasys system. This issue affects: Johnson Controls Metasys version 11.0 and prior versions.

01

remediations

Vendor fix, mitigation, or workaround guidance, as published by each source.

A vendor fix is available.

  • FixedMetasyscisa_csaf_ot

    Delete any user accounts if the user is no longer with the company or have been reassigned to another position where they no longer need to use Metasys.

  • MitigationMetasyscisa_csaf_ot

    Johnson Controls recommends that users of versions earlier than 9.0 upgrade to a supported release. Users of Version 9.0 (engine), 10.0, 10.1, or 11.0 are recommended to install the patch.

02

cvss

Technical severity, 0–10. One row per scoring source.

8.8
010

base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · medium–high · 6.5–8.8

v2.06.5mediumAV:N/AC:L/Au:S/C:P/I:P/A:Pprimary · NVD / NIST USexploitability 8 · impact 6.4
v3.18.8highCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:Hprimary · NVD / NIST USexploitability 2.8 · impact 5.9
v3.08.8highCVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:Hsecondary · CISA US
v3.18.8highCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:Hsecondary · ENISA EU
v3.18.8highCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:Hsecondary · productsecurity@jci.comexploitability 2.8 · impact 5.9
v3.18.1highCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:Usecondary · CVSS-BT (t0sche)
03

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-269USprimaryCWE-269US
04

affected products (4)

Products and version ranges known to be affected.

05

advisories (1)

Vendor and ecosystem advisories describing this.

  • ICSA-21-159-01Johnson Controls Metasys2021-06-08icsa · cisa_csaf_otUS

    Successful exploitation of this vulnerability could give an authenticated Metasys user an unintended level of access to the server file system, allowing them to access or modify system files by sending specifically crafted web messages to the Metasys system.

06

also known as (3)

Other names and identifiers for this entity.

07

sources

Which sources assert this record, and when.

cnnvdenisa_euvdcisa_csaf_otnvdNVDCVE.orgMITRE
published 2021-06-04modified 2026-06-17
09

references (11)

External citations — patches, advisories, analysis.

scry

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