Security readout for executives and security teams
Plain-English summary
CVE-2021-27660 affects Johnson Controls C-CURE 9000 before version 2.80. Its client auto-update feature is insecure and can let an authenticated lower-privileged attacker run Windows programs remotely, creating a serious risk to systems that manage security operations.
Executive priority
Treat this as a high-priority remediation item for any C-CURE 9000 environment below 2.80. The business concern is unauthorized code execution in security-management infrastructure, even though public active exploitation is not established in the provided sources.
Technical view
The flaw is CWE-20 improper input validation in the C-CURE 9000 client auto-update mechanism. CVSS 3.1 is 8.8: network reachable, low complexity, low privileges required, no user interaction, with high confidentiality, integrity, and availability impact.
Likely exposure
Exposure is limited to Johnson Controls C-CURE 9000 deployments running any version prior to 2.80. Confirm both server and client estate because the described weakness is in client auto update behavior.
Exploitation context
The provided sources do not report CISA KEV listing or active exploitation. The CVSS vector indicates exploitation requires low privileges but no user interaction and could be performed over the network if the vulnerable update path is reachable.
Researcher notes
Evidence is limited to the CVE record, vendor advisory reference, and CISA ICS advisory reference. The public summary does not describe exploit mechanics or detailed compensating controls, so validation should focus on version exposure and vendor guidance.
Mitigation direction
- Upgrade C-CURE 9000 to version 2.80 or later per vendor guidance.
- Review Johnson Controls security advisories for official remediation details.
- Limit C-CURE administrative and update-related access to trusted networks.
- Monitor Windows hosts running C-CURE clients for unexpected program execution.
Validation and detection
- Inventory all C-CURE 9000 servers and clients.
- Confirm whether any installed version is earlier than 2.80.
- Check whether client auto update is enabled in affected environments.
- Review relevant Windows logs for unusual program execution around update activity.
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-20: Exact CWE lookup
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Open ATT&CK lookupCVE-2021-27660 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
- 8.8 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
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:L/UI:N/S:U/C:H/I:H/A:H2.85.9Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
8.8HighVector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
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 Input Validation
Improper Input Validation represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.