[silverstripe/framework] Stored XSS using HTMLEditor

A malicious content author could add a JavaScript payload to the href attribute of a link by splitting a javascript URL with white space characters.

An attacker must have access to the CMS to exploit this issue.

References

• https://github.com/FriendsOfPHP/security-advisories/blob/master/silverstripe/framework/CVE-2022-37429.yaml
• https://www.silverstripe.org/download/security-releases/cve-2022-37429
• https://github.com/advisories/GHSA-wc6r-4ggc-79w5