CVE-2021-37698
Missing TLS service certificate validation in GelfWriter, ElasticsearchWriter, InfluxdbWriter and Influxdb2Writer
CVE-2021-37698 is a high vulnerability (CVSS 7.5) in Icinga, published August 19, 2021. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 1.38%, the 72nd percentile. Fixed in icinga2 2.12.6-r0.
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.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- High
- Integrity
- None
- Availability
- None
Exploit likelihood
What each source reports
CVE List Score used
7.5
Missing TLS service certificate validation in GelfWriter, ElasticsearchWriter, InfluxdbWriter and Influxdb2Writer
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.
- Record
CVE-2021-37698- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N - Weakness
- CWE-295
- Updated
- 2026-11-02
EUVDEUVD-2021-24193
7.5
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.
- Record
EUVD-2021-24193- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N - Updated
- 2026-11-02
NVD
7.5
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.
- Record
CVE-2021-37698- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N - CVSS 2.0
- 5.0 Medium
AV:N/AC:L/Au:N/C:P/I:N/A:N - Weakness
- CWE-295
- Updated
- 2026-11-02
OSVALPINE-CVE-2021-37698
7.5
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.
- Record
ALPINE-CVE-2021-37698- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N - Updated
- 2026-11-03
OSV
7.5
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.
- Record
CVE-2021-37698- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N - Updated
- 2026-11-02
OSVDEBIAN-CVE-2021-37698
7.5
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.
- Record
DEBIAN-CVE-2021-37698- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N - Updated
- 2026-11-02
OSVUBUNTU-CVE-2021-37698
7.5
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.
- Record
UBUNTU-CVE-2021-37698- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N - Updated
- 2026-11-02
OSVopenSUSE-SU-2024:10856-1 No score
icinga2-2.13.1-1.3 on GA media
These are all security issues fixed in the icinga2-2.13.1-1.3 package on the GA media of openSUSE Tumbleweed.
- Record
openSUSE-SU-2024:10856-1- Updated
- 2026-11-02
OSVSUSE-SU-2022:3725-1 No score
Security update for icinga2
This update for icinga2 fixes the following issues:
- CVE-2020-14004: prepare-dirs script allows for symlink attack in the icinga user context. (bsc#1172171)
- CVE-2020-29663: ignoring CRL, where revoked certificates due for renewal will automatically be renewed. (bsc#281137)
- CVE-2021-37698: Missing TLS server certificate validation in ElasticsearchWriter, GelfWriter, InfluxdbWriter and Influxdb2Writer. (bsc#281137)
- Record
SUSE-SU-2022:3725-1- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
icinga2Alpine:v3.14 |
before 2.12.6-r0 | 2.12.6-r0 |
icinga2Alpine:v3.15 |
before 2.13.1-r0 | 2.13.1-r0 |
icinga2Alpine:v3.16 |
before 2.13.1-r0 | 2.13.1-r0 |
icinga2Alpine:v3.17 |
before 2.13.1-r0 | 2.13.1-r0 |
icinga2Alpine:v3.18 |
before 2.13.1-r0 | 2.13.1-r0 |
icinga2Alpine:v3.19 |
before 2.13.1-r0 | 2.13.1-r0 |
icinga2Alpine:v3.20 |
before 2.13.1-r0 | 2.13.1-r0 |
icinga2Alpine:v3.21 |
before 2.13.1-r0 | 2.13.1-r0 |
icinga2Alpine:v3.22 |
before 2.13.1-r0 | 2.13.1-r0 |
icinga2Alpine:v3.23 |
before 2.13.1-r0 | 2.13.1-r0 |
Show 12 moreShow less
| Package | Affected | Fixed |
|---|---|---|
icinga2Alpine:v3.24 |
before 2.13.1-r0 | 2.13.1-r0 |
icinga2Debian:12 |
before 2.13.1-1 | 2.13.1-1 |
icinga2Debian:13 |
before 2.13.1-1 | 2.13.1-1 |
icinga2Debian:14 |
before 2.13.1-1 | 2.13.1-1 |
icinga2Debian:9 |
before 2.6.0-2+deb9u2, plus listed versions 2.6.0-22.6.0-2+deb9u1 |
2.6.0-2+deb9u2 |
icinga2Debian:11 |
before 2.12.3-1+deb11u1, plus listed versions 2.12.3-1 |
2.12.3-1+deb11u1 |
icinga2SUSE:Linux Enterprise Module for HPC 12 |
before 2.8.2-3.6.1 | 2.8.2-3.6.1 |
icinga2Ubuntu:16.04:LTS |
All versions, plus listed versions 2.3.8-1build12.3.11-12.4.0-12.4.1-12.4.1-22.4.1-2ubuntu1 |
None known |
icinga2Ubuntu:18.04:LTS |
All versions, plus listed versions 2.7.0-12.8.1-0ubuntu2 |
None known |
icinga2Ubuntu:20.04:LTS |
All versions, plus listed versions 2.10.5-1build12.11.2-12.11.2-1ubuntu12.11.2-1ubuntu22.11.2-1ubuntu3 |
None known |
icinga2Ubuntu:22.04:LTS |
All versions, plus listed versions 2.12.3-12.13.1-12.13.2-12.13.2-1build12.13.2-1build2 |
None known |
icinga2openSUSE:Tumbleweed |
before 2.13.1-1.3 | 2.13.1-1.3 |
History
| When | Changed | Sources |
|---|---|---|
| 2026-11-03 | affected, aliases, references | OSV |
| 2026-11-02 | created | CVE List, EUVD, NVD, OSV |
References
github.com/Icinga/icinga2/security/advisories/GHSA-cxfm-8j5v-5qr2
github.com/Icinga/icinga2/releases/tag/v2.11.11
github.com/Icinga/icinga2/releases/tag/v2.12.6
github.com/Icinga/icinga2/releases/tag/v2.13.1
lists.debian.org/debian-lts-announce/2021/11/msg00010.html
lists.debian.org/debian-lts-announce/2024/11/msg00010.html
Show 16 moreShow less
security.alpinelinux.org/vuln/CVE-2021-37698
security-tracker.debian.org/tracker/CVE-2021-37698
suse.com/support/update/announcement/2022/suse-su-20223725-1
bugzilla.suse.com/1172171
bugzilla.suse.com/1180147
bugzilla.suse.com/1189653
suse.com/security/cve/CVE-2020-14004
suse.com/security/cve/CVE-2020-29663
suse.com/security/cve/CVE-2021-37698
ubuntu.com/security/CVE-2021-37698
icinga.com/blog/2021/08/19/icinga-2-13-1-security-release
cve.org/CVERecord?id=CVE-2021-37698
suse.com/security/cve/CVE-2017-16933
suse.com/security/cve/CVE-2018-6534
suse.com/security/cve/CVE-2021-32739
suse.com/security/cve/CVE-2021-32743