Security readout for executives and security teams
Plain-English summary
Johnson Controls CEM Systems AC2000 versions 10.1 through 10.5 can allow remote access without adequate authorization. For organizations using AC2000 for physical security or access control, this could expose sensitive operational data and permit limited unauthorized changes.
Executive priority
Treat this as a high-priority exposure review for facilities using AC2000. The business risk is unauthorized access to a physical security management system, with strongest concern around sensitive data exposure.
Technical view
CVE-2021-27663 is an improper authorization issue, mapped to CWE-285. The CVSS 3.1 score is 8.2: network reachable, low complexity, no privileges, no user interaction, high confidentiality impact, low integrity impact, and no availability impact.
Likely exposure
Exposure is limited to environments running Johnson Controls CEM Systems AC2000 10.1, 10.2, 10.3, 10.4, or 10.5, especially where AC2000 services are reachable from untrusted networks.
Exploitation context
The provided sources do not show CISA KEV listing or confirmed active exploitation. The CVSS vector indicates unauthenticated remote exploitation may be possible, but the bundle does not provide exploit details or public weaponization evidence.
Researcher notes
The bundle identifies affected versions, CVSS, CWE-285, and advisory links, but does not include technical root cause details, fixed versions, mitigations, or exploit status beyond KEV=false. Validate against Johnson Controls and ICS-CERT guidance before final remediation planning.
Mitigation direction
- Check Johnson Controls security advisories for supported remediation guidance.
- Upgrade or patch affected AC2000 versions if vendor guidance provides a fixed release.
- Restrict AC2000 access to trusted management networks only.
- Review remote access paths into the access-control environment.
- Increase monitoring for unusual AC2000 authentication or access events.
Validation and detection
- Inventory AC2000 deployments and record exact versions.
- Confirm whether any deployment runs versions 10.1 through 10.5.
- Verify AC2000 is not exposed to the public internet.
- Review firewall and remote access rules for AC2000 services.
- Check logs for unexplained access attempts or unauthorized sessions.
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-285: 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-2021-27663 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
- 8.2 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N
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:L/PR:N/UI:N/S:U/C:H/I:L/A:N3.94.2Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
8.2HighVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N
Source materials
- CVE List V5 sourceCVE List V5
- https://www.johnsoncontrols.com/cyber-solutions/security-advisoriesCVE reference · x_refsource_CONFIRM
- ICS-CERT AdvisoryCVE reference · third-party-advisory, x_refsource_CERT
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 Authorization
Improper Authorization represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.