HOMEVULNERABILITIESCVE-2021-37698
HIGH

CVE-2021-37698

CWE-295Published: August 19, 2021· Updated: Jun 17, 2026

7.5
CVSS v3.1

Official 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.

NVD Source

Technical Analysis

CVE-2021-37698 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

The vulnerability requires no privileges and no user interaction, making it a prime target for automated exploitation campaigns and worm-like propagation.

A successful exploit results in complete confidentiality breach (data exposure), with a CVSS base score of 7.5.

CVSS v3.1 Vector Breakdown

Exploitability
Attack VectorNetwork
Attack ComplexityLow
Privileges Req.None
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

Affected Vendors & Products

Debian1 product(s)
debian linux
icinga1 product(s)
icinga
Source: NVD CPE · 2 total CPE entries

Exploit & PoC Resources

NO KNOWN EXPLOITNo public exploit confirmed at this time
Exploit-DB
Offensive Security exploit database
GitHub PoC Search
Community PoC repositories
Rapid7 / Metasploit
Metasploit module search
PacketStorm
Security advisories & exploits
NVD Detail
Official NIST entry
MITRE CVE
CVE Program entry
External links open in a new tab. Always verify in a controlled environment before use.

Official Patches & Advisories

ADVISORYhttps://github.com/Icinga/icinga2/releases/tag/v2.11.11
ADVISORYhttps://github.com/Icinga/icinga2/releases/tag/v2.12.6
ADVISORYhttps://github.com/Icinga/icinga2/releases/tag/v2.13.1
ADVISORYhttps://github.com/Icinga/icinga2/security/advisories/GHSA-cxfm-8j5v-5qr2
ADVISORYhttps://lists.debian.org/debian-lts-announce/2021/11/msg00010.html
ADVISORYhttps://github.com/Icinga/icinga2/releases/tag/v2.11.11
ADVISORYhttps://github.com/Icinga/icinga2/releases/tag/v2.12.6
ADVISORYhttps://github.com/Icinga/icinga2/releases/tag/v2.13.1
ADVISORYhttps://github.com/Icinga/icinga2/security/advisories/GHSA-cxfm-8j5v-5qr2
ADVISORYhttps://lists.debian.org/debian-lts-announce/2021/11/msg00010.html

All References (11)

→
https://github.com/Icinga/icinga2/releases/tag/v2.11.11Release Notes · Third Party Advisory
→
https://github.com/Icinga/icinga2/releases/tag/v2.12.6Release Notes · Third Party Advisory
→
https://github.com/Icinga/icinga2/releases/tag/v2.13.1Release Notes · Third Party Advisory
→
https://github.com/Icinga/icinga2/security/advisories/GHSA-cxfm-8j5v-5qr2Third Party Advisory
→
https://lists.debian.org/debian-lts-announce/2021/11/msg00010.htmlMailing List · Third Party Advisory
→
https://github.com/Icinga/icinga2/releases/tag/v2.11.11Release Notes · Third Party Advisory
→
https://github.com/Icinga/icinga2/releases/tag/v2.12.6Release Notes · Third Party Advisory
→
https://github.com/Icinga/icinga2/releases/tag/v2.13.1Release Notes · Third Party Advisory
→
https://github.com/Icinga/icinga2/security/advisories/GHSA-cxfm-8j5v-5qr2Third Party Advisory
→
https://lists.debian.org/debian-lts-announce/2021/11/msg00010.htmlMailing List · Third Party Advisory
→
https://lists.debian.org/debian-lts-announce/2024/11/msg00010.html

Quick Facts

CVE IDCVE-2021-37698
CVSS Score7.5 / 10
SeverityHIGH
WeaknessCWE-295
CISA KEVNo
Affected2 vendor(s)
PublishedAug 19, 2021

Related CVEs (CWE-295)

CVE-2026-4370
10.0
CVE-2020-7956
9.8
CVE-2018-4991
9.8
CVE-2018-9127
9.8
CVE-2010-1378
9.8
CVE-2019-1010275
9.8

Recommended Actions

  • →Apply vendor patches immediately
  • →Monitor CVE-2021-37698 in threat intel feeds
  • →Review IDS/IPS signatures for exploitation attempts
Data sourced from NVD (NIST), CISA KEV, and EPSS (FIRST). Analysis generated by CTIWATCH.COM. CVE data is provided under the NVD usage policy.
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