CVE & CISA-KEV Catalog

CVE-2021-30191

HIGH

7.5

CVSS v3

Description

CODESYS V2 Web-Server before 1.1.9.20 has a a Buffer Copy without Checking the Size of the Input.

CWE-120Classic Buffer Overflow

How to fix

Remediation Available

750-8202 firmwareNVD

Affected:< 03.06.19_(18)Fixed in:03.06.19_(18)CVE-2021-30191derived from NVD

750-8203 firmwareNVD

Affected:< 03.06.19_(18)Fixed in:03.06.19_(18)CVE-2021-30191derived from NVD

750-8204 firmwareNVD

Affected:< 03.06.19_(18)Fixed in:03.06.19_(18)CVE-2021-30191derived from NVD

750-8206 firmwareNVD

Affected:< 03.06.19_(18)Fixed in:03.06.19_(18)CVE-2021-30191derived from NVD

750-8207 firmwareNVD

Affected:< 03.06.19_(18)Fixed in:03.06.19_(18)CVE-2021-30191derived from NVD

750-8208 firmwareNVD

Affected:< 03.06.19_(18)Fixed in:03.06.19_(18)CVE-2021-30191derived from NVD

750-8210 firmwareNVD

Affected:< 03.06.19_(18)Fixed in:03.06.19_(18)CVE-2021-30191derived from NVD

750-8211 firmwareNVD

Affected:< 03.06.19_(18)Fixed in:03.06.19_(18)CVE-2021-30191derived from NVD

750-8212 firmwareNVD

Affected:< 03.06.19_(18)Fixed in:03.06.19_(18)CVE-2021-30191derived from NVD

750-8213 firmwareNVD

Affected:< 03.06.19_(18)Fixed in:03.06.19_(18)CVE-2021-30191derived from NVD

750-8214 firmwareNVD

Affected:< 03.06.19_(18)Fixed in:03.06.19_(18)CVE-2021-30191derived from NVD

750-8216 firmwareNVD

Affected:< 03.06.19_(18)Fixed in:03.06.19_(18)CVE-2021-30191derived from NVD

750-8217 firmwareNVD

Affected:< 03.06.19_(18)Fixed in:03.06.19_(18)CVE-2021-30191derived from NVD

750-823 firmwareNVD

Affected:< fw08Fixed in:fw08CVE-2021-30191derived from NVD

750-829 firmwareNVD

Affected:< fw15Fixed in:fw15CVE-2021-30191derived from NVD

750-831 firmwareNVD

Affected:< fw15Fixed in:fw15CVE-2021-30191derived from NVD

750-832 firmwareNVD

Affected:< fw08Fixed in:fw08CVE-2021-30191derived from NVD

750-852 firmwareNVD

Affected:< fw15Fixed in:fw15CVE-2021-30191derived from NVD

750-862 firmwareNVD

Affected:< fw08Fixed in:fw08CVE-2021-30191derived from NVD

750-880 firmwareNVD

Affected:< fw16Fixed in:fw16CVE-2021-30191derived from NVD

750-881 firmwareNVD

Affected:< fw15Fixed in:fw15CVE-2021-30191derived from NVD

750-882 firmwareNVD

Affected:< fw15Fixed in:fw15CVE-2021-30191derived from NVD

750-885 firmwareNVD

Affected:< fw15Fixed in:fw15CVE-2021-30191derived from NVD

750-889 firmwareNVD

Affected:< fw15Fixed in:fw15CVE-2021-30191derived from NVD

750-890 firmwareNVD

Affected:< fw08Fixed in:fw08CVE-2021-30191derived from NVD

750-891 firmwareNVD

Affected:< fw08Fixed in:fw08CVE-2021-30191derived from NVD

750-893 firmwareNVD

Affected:< fw08Fixed in:fw08CVE-2021-30191derived from NVD

v2 web serverNVD

Affected:< 1.1.9.20Fixed in:1.1.9.20CVE-2021-30191derived from NVD

Remediation is compiled from vendor and distribution security advisories. Always confirm against the linked source for your exact version and platform.

CVSS v3 Vector

Exploitability

Attack VectorNetwork

Attack ComplexityLow

Privileges RequiredNone

User InteractionNone

ScopeUnchanged

Impact

ConfidentialityNone

IntegrityNone

AvailabilityHigh

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

Exploit Intelligence

1.02%probability of exploitation in 30 days

59thpercentile

Moderate risk: more likely to be exploited than 59% of all known CVEs.

References

Vendor Advisory2

Related Vulnerabilities

Other CWE-120 (Classic Buffer Overflow) vulnerabilities, ordered by exploit likelihood. View all

CVE	Severity	CVSS	EPSS	Exploited	Fix
CVE-2014-0195	Medium	6.8	100%	-	Fix
CVE-2017-7269	Critical	9.8	100%	KEV	-
CVE-2019-11043	High	8.7	99%	KEV + Ransom	Fix
CVE-2011-4862	High	10.0	95%	-	Fix
CVE-2007-5659	High	7.8	94%	KEV	Fix
CVE-2022-3786	High	7.5	91%	-	Fix

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This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2025-08-15.