Is CVE-2021-3377 in the CISA KEV catalog?

No. CVE-2021-3377 is not currently on the CISA Known Exploited Vulnerabilities list.

What is the CVSS severity of CVE-2021-3377?

CVE-2021-3377 has a CVSS v3 base score of 6.1 (MEDIUM).

What is the EPSS score for CVE-2021-3377?

CVE-2021-3377 has an EPSS score of 8.00% (94th percentile), estimating the probability of exploitation in the next 30 days.

How do I fix CVE-2021-3377?

Upgrade node-ansi-up on debian 11 to 5.0.0+dfsg-1 or later.

CVE & CISA-KEV Catalog

CVE-2021-3377

MEDIUMEPSS 94th pctl

6.1

CVSS v3

NVD

Description

The npm package ansi_up converts ANSI escape codes into HTML. In ansi_up v4, ANSI escape codes can be used to create HTML hyperlinks. Due to insufficient URL sanitization, this feature is affected by a cross-site scripting (XSS) vulnerability. This issue is fixed in v5.0.0.

CWE-79Cross-Site Scripting (XSS)

How to fix

Remediation Available

node-ansi-upDebian

Fixed in:5.0.0+dfsg-1CVE-2021-3377

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

8.00%probability of exploitation in 30 days

94thpercentile

High risk: more likely to be exploited than 94% of all known CVEs.

References

Patch1

github.com

Exploit1

doyensec.com

Other references1

security.netapp.com

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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Markdown

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HTML

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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 2025-11-03.