Is CVE-2021-37698 in the CISA KEV catalog?

No. CVE-2021-37698 is not currently on the CISA Known Exploited Vulnerabilities list.

What is the CVSS severity of CVE-2021-37698?

CVE-2021-37698 has a CVSS v3 base score of 7.5 (HIGH).

What is the EPSS score for CVE-2021-37698?

CVE-2021-37698 has an EPSS score of 1.42% (70th percentile), estimating the probability of exploitation in the next 30 days.

How do I fix CVE-2021-37698?

Upgrade icinga2 on debian 11 to 2.12.3-1+deb11u1 or later.

CVE & CISA-KEV Catalog

CVE-2021-37698

HIGH

7.5

CVSS v3

NVD

Description

Icinga is a monitoring system which checks the availability of network resources, notifies users of outages, and generates performance data for reporting. In versions 2.5.0 through 2.13.0, ElasticsearchWriter, GelfWriter, InfluxdbWriter and Influxdb2Writer do not verify the server's certificate despite a certificate authority being specified. Icinga 2 instances which connect to any of the mentioned time series databases (TSDBs) using TLS over a spoofable infrastructure should immediately upgrade to version 2.13.1, 2.12.6, or 2.11.11 to patch the issue. Such instances should also change the credentials (if any) used by the TSDB writer feature to authenticate against the TSDB. There are no workarounds aside from upgrading.

CWE-295Improper Certificate Validation

How to fix

Remediation Available

icinga2Debian

Fixed in:2.12.3-1+deb11u1CVE-2021-37698

Fixed in:2.13.1-1CVE-2021-37698

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

ConfidentialityHigh

IntegrityNone

AvailabilityNone

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

Exploit Intelligence

1.42%probability of exploitation in 30 days

70thpercentile

Moderate risk: more likely to be exploited than 70% of all known CVEs.

References

Third-Party Advisory5

Other references1

lists.debian.org

Related Vulnerabilities

Other CWE-295 (Improper Certificate Validation) vulnerabilities, ordered by exploit likelihood. View all

CVE	Severity	CVSS	EPSS	Exploited	Fix
CVE-2015-4000	Low	3.7	100%	-	Fix
CVE-2020-0601	High	8.1	89%	KEV	Fix
CVE-2009-3555	Critical	9.8	87%	-	Fix
CVE-2022-26923	High	8.8	83%	KEV	Fix
CVE-2023-27823	Critical	9.8	53%	-	-
CVE-2022-42979	High	8.8	24%	-	-

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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.