SB2021102933 - Inefficient regular expression complexity in Fluentd

Description

This security bulletin contains information about 1 vulnerability.

1) Inefficient regular expression complexity (CVE-ID: CVE-2021-41186)

CWE-ID: CWE-1333 - Inefficient Regular Expression Complexity

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green

The vulnerability allows a remote attacker to cause a denial of service.

The vulnerability exists due to improper input validation in parser_apache2 when parsing broken apache log entries containing a certain string pattern. A remote attacker can supply a specially crafted log entry to cause a denial of service.

Remediation

Install update from vendor's website.

References

• https://github.com/fluent/fluentd/security/advisories/GHSA-hwhf-64mh-r662
• https://securitylab.github.com/advisories/GHSL-2021-102-fluent-fluentd/