CVE-2021-22138

Severity: low (CVSS 3.7 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.5% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2021-05-13 · updated 2026-06-17
Weakness: CWE-295

Description

In Logstash versions after 6.4.0 and before 6.8.15 and 7.12.0 a TLS certificate validation flaw was found in the monitoring feature. When specifying a trusted server CA certificate Logstash would not properly verify the certificate returned by the monitoring server. This could result in a man in the middle style attack against the Logstash monitoring data.

Affected products

Elastic Logstash: from 6.4.0 before 6.8.15; from 7.0.0 before 7.12.0 — fixed in 6.8.15, 7.12.0

How to fix

Upgrade to a fixed version: Elastic Logstash 6.8.15, 7.12.0. Check the vendor advisory for mitigations.

References

https://discuss.elastic.co/t/elastic-stack-7-12-0-and-6-8-15-security-update/268125
https://security.netapp.com/advisory/ntap-20210629-0001/
https://discuss.elastic.co/t/elastic-stack-7-12-0-and-6-8-15-security-update/268125
https://security.netapp.com/advisory/ntap-20210629-0001/

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