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TI-2021-15573 Aliases CVE-2021-37698

Missing TLS service certificate validation in GelfWriter, ElasticsearchWriter, InfluxdbWriter and Influxdb2Writer

Priority LOW 36CWE-295Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Impact type
Spoofing
Confidentiality · integrity · availability
High · None · None
Fix status
No fix listed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA. Impact type from CWE-295.

Summary

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.

Why it matters now

EPSS 0.01381 72nd percentileScored 2026-11-07
Fix No fix listed No fixed version in the sources yet

SSVC decision points

Not available: CISA has not published SSVC decision points for this record.

Affected products

VendorProductAffected versionsFixed inStatusSource
Icingaicinga22.5.0 – 2.13.0—No fix listedCNA
  • icinga2 VendorIcinga Affected 2.5.0 – 2.13.0 Fixed in — No fix listed CNA

CPE configurations NVD · 2

CPEVersionsRoleVendor
cpe:2.3:a:icinga:icinga:*:*:*:*:*:*:*:*2.5.0 to before 2.11.10; 2.12.0 to before 2.12.6; 2.13.0 to before 2.13.1VulnerableIcinga
cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:*9.0VulnerableDebian
  • cpe:2.3:a:icinga:icinga:*:*:*:*:*:*:*:* Versions 2.5.0 to before 2.11.10; 2.12.0 to before 2.12.6; 2.13.0 to before 2.13.1 Vulnerable ·Icinga
  • cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:* Versions 9.0 Vulnerable ·Debian

Remediation

No fixed version listed by the sources yet.

Timeline

  1. 2026-10-02 Threatist record created from CVE-2021-37698

References

Advisory 5

  • TI-2024-16337 Icinga Director configuration is susceptible to Cross-Site Request Forgery CVSS 3.1HIGH 8.3
  • TI-2012-05060 Multiple stack-based buffer overflows in the get_history function in history.cgi in… CVSS 2.0HIGH 7.5
  • TI-2013-05840 Multiple off-by-one errors in Nagios Core 3.5.1, 4.0.2, and earlier, and Icinga before… CVSS 2.0MEDIUM 5.5
  • TI-2024-32957 Icinga 2 has a TLS Certificate Validation Bypass for JSON-RPC and HTTP API Connections CVSS 3.1CRITICAL 9.8
  • TI-2025-30428 Icinga 2 certificate renewal might incorrectly renew an invalid certificate CVSS 4.0CRITICAL 9.3
  • TI-2021-12411 Passwords used to access external services inadvertently exposed through API CVSS 3.1HIGH 8.8
See all 30 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences