Is CVE-2021-43977 in the CISA KEV catalog?

No. CVE-2021-43977 is not currently on the CISA Known Exploited Vulnerabilities list.

What is the CVSS severity of CVE-2021-43977?

CVE-2021-43977 has a CVSS v3 base score of 6.1 (MEDIUM).

What is the EPSS score for CVE-2021-43977?

CVE-2021-43977 has an EPSS score of 0.57% (43th percentile), estimating the probability of exploitation in the next 30 days.

How do I fix CVE-2021-43977?

Upgrade smartermail to 100.0.7803 or later.

CVE & CISA-KEV Catalog

CVE-2021-43977

MEDIUM

6.1

CVSS v3

NVD

Description

SmarterTools SmarterMail 16.x through 100.x before 100.0.7803 allows XSS.

CWE-79Cross-Site Scripting (XSS)

How to fix

Remediation Available

smartermailNVD

Affected:>= 16.0.6345, < 100.0.7803Fixed in:100.0.7803CVE-2021-43977derived 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 InteractionRequired

ScopeChanged

Impact

ConfidentialityLow

IntegrityLow

AvailabilityNone

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

Exploit Intelligence

0.57%probability of exploitation in 30 days

43rdpercentile

Moderate risk: more likely to be exploited than 43% of all known CVEs.

References

Vendor Advisory1

smartertools.com

Third-Party Advisory1

csirt.divd.nl

Related Vulnerabilities

Other CWE-79 (Cross-Site Scripting (XSS)) vulnerabilities, ordered by exploit likelihood. View all

CVE	Severity	CVSS	EPSS	Exploited	Fix
CVE-2020-11022	Medium	6.9	99%	-	Fix
CVE-2019-3929	Critical	9.8	99%	KEV	Fix
CVE-2020-9496	Medium	6.1	99%	-	-
CVE-2023-28341	Medium	6.1	99%	-	Fix
CVE-2018-12998	Medium	6.1	98%	-	-
CVE-2025-4123	High	7.6	98%	-	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 2024-11-21.