How severe is CVE-2021-23155?

CVE-2021-23155 has a CVSS 3.x base score of 9.0, rated critical severity. It is exploitable over network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2021-23155 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (37th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-23155?

CVE-2021-23155 affects Gallagher Command Centre Mobile Client. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-23155?

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

When was CVE-2021-23155 published?

CVE-2021-23155 was published on 2021-11-18 and last updated on 2026-06-17.

CVE-2021-23155

CVE-2021-23155 is a critical-severity vulnerability in Gallagher Command Centre Mobile Client with a CVSS 3.x base score of 9.0. 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-295.

Key facts

Severity: Critical (CVSS 3.x base score 9.0)
CVSS v2: 4.3
EPSS exploit prediction: 0% (37th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-295
Affected product: Gallagher Command Centre Mobile Client
Published: 2021-11-18
Last modified: 2026-06-17

Description

Improper validation of the cloud certificate chain in Mobile Client allows man-in-the-middle attack to impersonate the legitimate Command Centre Server. This issue affects: Gallagher Command Centre Mobile Client for Android 8.60 versions prior to 8.60.065; version 8.50 and prior versions.

Frequently asked questions

What is CVE-2021-23155?: Improper validation of the cloud certificate chain in Mobile Client allows man-in-the-middle attack to impersonate the legitimate Command Centre Server. This issue affects: Gallagher Command Centre Mobile Client for Android 8.60 versions prior to 8.60.065; version 8.50 and prior versions.
How severe is CVE-2021-23155?: CVE-2021-23155 has a CVSS 3.x base score of 9.0, rated critical severity. It is exploitable over network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2021-23155 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (37th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-23155?: CVE-2021-23155 affects Gallagher Command Centre Mobile Client. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-23155?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
When was CVE-2021-23155 published?: CVE-2021-23155 was published on 2021-11-18 and last updated on 2026-06-17.

References

https://security.gallagher.com/Security-Advisories/CVE-2021-23155

Affected products (1)

cpe:2.3:a:gallagher:command_centre_mobile_client:*:*:*:*:*:android:*:*

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