[org.apache.struts:struts2-core] Possible DoS attack when using URLValidator

If an application allows enter an URL in a form field and built-in URLValidator is used, it is possible to prepare a special URL which will be used to overload server process when performing validation of the URL.

References

• https://nvd.nist.gov/vuln/detail/CVE-2016-8738
• https://security.netapp.com/advisory/ntap-20180629-0003/
• https://struts.apache.org/docs/s2-044.html
• https://github.com/advisories/GHSA-86vq-8qhc-5rqw