What is CVE-2021-4105?

CVE-2021-4105 is a critical-severity vulnerability in Bg-Tek Coslat Bx5s1d3, classified under Improper Handling of Exceptional Conditions. CVSS score: 9.8/10. Published 2023-02-24.

How severe is CVE-2021-4105?

Critical severity. CVSS v3 base score is 9.8 out of 10.

Vulnerability in Bg-Tek Coslat Bx5s1d3

CVE-2021-4105

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.

Published 2023-02-24 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.009 (57.3th percentile), scored 2026-10-01.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 57th percentile — 57.3% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.009 · newest: 0.009 · change: 0.000

Affected products

Weakness classification (CWE)

CWE-755 — Improper Handling of Exceptional Conditions

References

blog.coslat.com/2021/07/onemli-kritik-guncelleme-2021-07-27.html (vendor-advisory, Vendor Advisory)
www.usom.gov.tr/bildirim/tr-23-0108 (Third Party Advisory, government-resource, broken-link)
siberguvenlik.gov.tr/guvenlik-bildirimleri/detay/tr-23-0108 (government-resource)

Frequently asked questions

What is CVE-2021-4105?: CVE-2021-4105 is a critical-severity vulnerability in Bg-Tek Coslat Bx5s1d3, classified under Improper Handling of Exceptional Conditions. CVSS score: 9.8/10. Published 2023-02-24.
How severe is CVE-2021-4105?: Critical severity. CVSS v3 base score is 9.8 out of 10.