This is a bug-fix release. Some of the fixes are security-related.
The details of the vulnerabilities being fixed can be found in the links below. Users are encouraged to upgrade to 2.2.4 if they are affected or unsure.
- fix crash when logging TLS 1.3 properties (CVE-2017-10872) (reported by MITSUNARI Shigeo)
- fix crash when handling malformed HTTP/2 request (CVE-2017-10908) (reported by Eiichi Tsukata)