Vulnerability Snapshot
CVE-2021-4105 is rated CRITICAL — exploitation is trivial or already observed in the wild and impact is severe. Patch immediately, not on the next maintenance window.
Affected technology: coslat_bx5s1d3_firmware, coslat_bx5s1d3, coslat_bx5s1d4_firmware, coslat_bx5s1d4, coslat_bx5s1d5_firmware, plus 5 other product variants.
Executive Summary
Improper Handling of Parameters vulnerability in BG-TEK COSLAT Firewall allows Remote Code Inclusion.
This issue affects COSLAT Firewall: from 5.24.0.R.20180630 before 5.24.0.R.20210727.
Why It Matters
CVE-2021-4105 is rated CRITICAL severity, requiring immediate attention from security teams.
CVSS Base Score: 9.8/10
EPSS (Exploit Prediction): 0.6% probability of exploitation in the next 30 days.
Affected Technologies
Vendors: bg-tek
Products: coslat_bx5s1d3_firmware, coslat_bx5s1d3, coslat_bx5s1d4_firmware, coslat_bx5s1d4, coslat_bx5s1d5_firmware, coslat_bx5s1d5, coslat_rm1ds1000_firmware, coslat_rm1ds1000, coslat_rm2ds2000_firmware, coslat_rm2ds2000, coslat_rm2s200_firmware, coslat_rm2s200, coslat_rm3s300_firmware, coslat_rm3s300, coslat_rm4s500_firmware, coslat_rm4s500
🛡️What Defenders Should Check
Use Vulnios to continuously monitor your exposure to CVE-2021-4105 and similar vulnerabilities.
References & Sources
How Vulnios Detects This
Vulnios scans for this vulnerability using Trivy and Grype for SBOM-based CVE matching and Vulnios CVE feed continuous monitoring against your asset inventory. Run a scan against your environment to see whether you are exposed; findings are linked back to the original CVE record so triage starts with the patch path already known.
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Affected Products
Sources
Related Threat Alerts
Frequently Asked Questions
What is CVE-2021-4105?
CVE-2021-4105 is a critical-severity vulnerability tracked under the Common Vulnerabilities and Exposures program. Improper Handling of Parameters vulnerability in BG-TEK COSLAT Firewall allows Remote Code Inclusion.
This issue affects COSLAT Firewall: from 5.24.0.R.20180630 before 5.24.0.R.20210727.
Am I affected?
Check whether your environment runs coslat_bx5s1d3_firmware, coslat_bx5s1d3, coslat_bx5s1d4_firmware, coslat_bx5s1d4, coslat_bx5s1d5_firmware. If you operate any of those, treat yourself as in scope until you have evidence otherwise. A Vulnios scan will identify the exact assets carrying the affected version.
How urgent is the response?
Critical: do not wait for your normal patch cycle. Verify exposure today, apply the vendor patch immediately, and add detection rules for any post-exploit indicators.
How do I remediate?
Apply the vendor patch listed in the upstream advisory linked under Sources. If the patch is not yet available, follow the vendor-supplied workaround (often a config flag or feature disable) and add detections for the published exploit pattern in your SIEM. Re-scan after the patch lands to confirm the finding clears.
Where can I track exploitation activity?
Watch CISA's Known Exploited Vulnerabilities catalog for CVE-2021-4105. Cross-reference with public exploit databases and your own SIEM/IDS for indicator-of-compromise patterns. Vulnios tracks KEV status automatically and surfaces it on the asset findings view.
How does Vulnios help with this?
Vulnios continuously cross-references your asset inventory against the live CVE feed (NVD, vendor advisories, CISA KEV, and curated OSINT). When a new CVE matches your environment, you get a prioritized finding with the severity, KEV status, exploit-prediction (EPSS), and a direct path to the vendor patch. You can start a free scan from the homepage.
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