Security readout for executives and security teams
Plain-English summary
Gallagher Command Centre can fail to properly validate SMTP certificates, allowing a network man-in-the-middle to intercept sensitive information from the Command Centre Server. The issue is high severity because email transport can carry operationally sensitive data, but the CVSS vector rates attack complexity as high.
Executive priority
Prioritize remediation for Command Centre environments that send email alerts or sensitive operational messages. The business concern is confidentiality loss through intercepted SMTP traffic, especially in physical security operations where Command Centre data may reveal security events or system state.
Technical view
CVE-2021-23167 is CWE-295 improper certificate validation in the Command Centre SMTP Client. A network attacker positioned for man-in-the-middle traffic could retrieve sensitive information from the Command Centre Server. Affected releases include 8.50 before 8.50.2048, 8.40 before 8.40.2063, 8.30 before 8.30.1454, and 8.20 or earlier.
Likely exposure
Organizations running Gallagher Command Centre versions below the listed maintenance releases, or 8.20 and earlier, are potentially exposed. Risk is most relevant where the Command Centre Server uses SMTP client functionality for email delivery.
Exploitation context
The source bundle does not show CISA KEV listing or any cited evidence of active exploitation. Exploitation requires network man-in-the-middle positioning and is rated high attack complexity, with no privileges or user interaction required.
Researcher notes
Evidence is limited to the CVE metadata and Gallagher advisory reference in the bundle. Do not claim public exploitation without additional sources. Key validation points are product version, SMTP client use, and whether each deployment is below the fixed maintenance release named for its branch.
Mitigation direction
- Upgrade 8.50 deployments to 8.50.2048 MR3 or later.
- Upgrade 8.40 deployments to 8.40.2063 MR4 or later.
- Upgrade 8.30 deployments to 8.30.1454 MR4 or later.
- For 8.20 or earlier, check Gallagher guidance for a supported fixed upgrade path.
- Review Gallagher’s advisory before applying operational mitigations.
Validation and detection
- Inventory all Gallagher Command Centre Server versions.
- Confirm whether SMTP client functionality is enabled or configured.
- Compare installed versions against the affected release thresholds.
- Verify upgraded systems report the target maintenance release or later.
- Document any 8.20 or older deployments as unresolved until vendor guidance is applied.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-295: Exact CWE lookup
Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCVE-2021-23167 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- High
- CVSS
- 8.1 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:L/A:L
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:L/A:L2.25.3Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
8.1HighVector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:L/A:L
Source materials
- CVE List V5 sourceCVE List V5
- https://security.gallagher.com/Security-Advisories/CVE-2021-23167CVE reference · x_refsource_MISC
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Improper Certificate Validation
Improper Certificate Validation represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.