Improper Certificate Validation in Icinga - CVE-2021-37698
Published: August 19, 2021 / Updated: June 29, 2026
Vulnerability identifier: #VU135832
CSH Severity: Medium
CVSS v4: 6.9 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N]
CVE-ID: CVE-2021-37698
CWE-ID: CWE-295
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to intercept sensitive information.
The vulnerability exists due to improper certificate validation in ElasticsearchWriter, GelfWriter, InfluxdbWriter, and Influxdb2Writer when establishing TLS connections to configured TSDB servers. A remote attacker can present a spoofed certificate to intercept sensitive information.
Exploitation requires a spoofable network infrastructure between the affected instance and the target TSDB service.
Affected software
Icinga
Gentoo Linux
net-analyzer/icinga2
Gentoo Linux
net-analyzer/icinga2
How to mitigate CVE-2021-37698
Install security update from vendor's website.
Icinga - addressed in versions 2.7.0, 2.8.0, 2.9.0, 2.10.0, 2.11.0, 2.12.0, 2.13.0, 2.13.1
net-analyzer/icinga2 - update to 2.14.3
net-analyzer/icinga2 - update to 2.14.3