Predictive Vulnerability Intelligence.

Product

  • Product
  • Pricing
  • Documentation

Company

  • About
  • Partnerships
  • Blog
  • Support

Legal

  • Terms
  • Privacy
  • Data Licensing

© 2026 FAUCET Technologies LLC. All rights reserved.

CVE-2021-27661

27
FAUCET Score

CVE-2021-27661 is a high-severity vulnerability affecting Johnson Controls Facility Explorer SNC Series Supervisory Controllers (F4-SNC) and their firmware. An authenticated user can exploit this flaw by sending specially crafted web messages, gaining unintended access to the controller's file system, and potentially modifying or accessing system files. With a CVSS score of 8.8, this vulnerability allows for high impact on confidentiality, integrity, and availability with low attack complexity and no user interaction required. There is currently no evidence of active exploitation, public exploit code (Metasploit, Nuclei, ExploitDB), or significant community discussion or media coverage surrounding this CVE.

Impacted Technologies

VendorProductVersion(s)CPE
11CPE matchmatch criteria
cpe:2.3:o:johnsoncontrols:f4-snc_firmware:11:*:*:*:*:*:*:*

CVSS Data

CVSS version used by this source: 3.1

8.8HIGH

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
HIGH
Integrity Impact
HIGH
Availability Impact
HIGH
Exploitability Score
2.8
Impact Score
5.9
CvssVersion
3.1

Exploit Intelligence

EPSS Score
0.82%
Probability of exploitation in next 30 days
EPSS Percentile
53.4%
Percentile rank of EPSS score among Peer Group
As of 2026-07-28
Model: v2026.06.15
This CVE's current EPSS score of 0.0082 is in the 48th percentile among its peer group of 17,844 CVEs.

Social Chatter

The average CVE in this peer group has 0.0 Twitter, 0.0 Reddit, 0.3 Bluesky, 0.1 Mastodon, and 0.2 GitHub mentions.

Media Mentions

No media coverage found for this CVE.

The average CVE in this peer group has 0.1 InfoSec Media, 0.0 Vendor Blog, and 0.0 Security Researcher mentions.

Remediation

Remediation records are not available for this CVE.

References

us-cert.cisa.gov / ics/advisories/icsa-21-182-01
Third Party AdvisoryUS Government Resource
johnsoncontrols.com / cyber-solutions/security-advisories
Vendor Advisory