How severe is CVE-2021-27660?

CVE-2021-27660 has a CVSS 3.x base score of 8.8, rated high severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2021-27660 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (79th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-27660?

CVE-2021-27660 affects Johnsoncontrols C-cure 9000 Firmware. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-27660?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2021-27660 published?

CVE-2021-27660 was published on 2021-07-01 and last updated on 2026-06-17.

CVE-2021-27660

CVE-2021-27660 is a high-severity vulnerability in Johnsoncontrols C-cure 9000 Firmware with a CVSS 3.x base score of 8.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-20.

Key facts

Severity: High (CVSS 3.x base score 8.8)
CVSS v2: 6.5
EPSS exploit prediction: 2% (79th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-20
Affected product: Johnsoncontrols C-cure 9000 Firmware
Published: 2021-07-01
Last modified: 2026-06-17

Description

An insecure client auto update feature in C-CURE 9000 can allow remote execution of lower privileged Windows programs.

Frequently asked questions

What is CVE-2021-27660?: An insecure client auto update feature in C-CURE 9000 can allow remote execution of lower privileged Windows programs.
How severe is CVE-2021-27660?: CVE-2021-27660 has a CVSS 3.x base score of 8.8, rated high severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2021-27660 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (79th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-27660?: CVE-2021-27660 affects Johnsoncontrols C-cure 9000 Firmware. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-27660?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2021-27660 published?: CVE-2021-27660 was published on 2021-07-01 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:o:johnsoncontrols:c-cure_9000_firmware:*:*:*:*:*:*:*:*

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