cvedb.io
CVE-2021-41186
MEDIUM · CVSS 5.9
EPSS exploitation probability: 0%
Published 2021-10-29T14:15:07.730 · Last modified 2026-06-17T04:08:03.120

Summary

Fluentd collects events from various data sources and writes them to files to help unify logging infrastructure. The parser_apache2 plugin in Fluentd v0.14.14 to v1.14.1 suffers from a regular expression denial of service (ReDoS) vulnerability. A broken apache log with a certain pattern of string can spend too much time in a regular expression, resulting in the potential for a DoS attack. This issue is patched in version 1.14.2 There are two workarounds available. Either don't use parser_apache2 for parsing logs (which cannot guarantee generated by Apache), or put patched version of parser_apache2.rb into /etc/fluent/plugin directory (or any other directories specified by the environment variable `FLUENT_PLUGIN` or `--plugin` option of fluentd).

Affected products

fluentd — fluentd

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References

This product uses data from the NVD API but is not endorsed or certified by the NVD. Informational only; not professional security advice.