Description
WordPress is prone to a Denial of Service vulnerability which can be exploited by malicious people to cause the affected website to consume memory and CPU resources, thus denying service to legitimate users. WordPress versions 4.1.x ranging from 4.1 and up to (and including) 4.1.22 are vulnerable.
Remediation
Evaluate and apply the suggested patch
References
https://baraktawily.blogspot.ro/2018/02/how-to-dos-29-of-world-wide-websites.html
https://www.youtube.com/watch?v=nNDsGTalXS0
https://github.com/Quitten/WordPress/blob/master/wp-dos-patch.sh
https://www.exploit-db.com/exploits/43968/
https://packetstormsecurity.com/files/146249/WordPress-Core-Denial-Of-Service.html
https://www.rastating.com/protecting-wordpress-against-cve-2018-6389/
Related Vulnerabilities
PHP Use After Free Vulnerability (CVE-2016-6290)
WordPress Plugin Erident Custom Login and Dashboard Cross-Site Scripting (3.5.8)
Dotclear Unrestricted Upload of File with Dangerous Type Vulnerability (CVE-2016-9268)
Undertow Exposure of Sensitive Information to an Unauthorized Actor Vulnerability (CVE-2020-1745)