Authenticated users with Administrator or Developer roles may execute OS commands by Groovy Script which uses Groovy lib to render a webpage. The groovy script does not have security restrictions, which will cause attackers to execute arbitrary commands remotely(RCE).

References

• https://nvd.nist.gov/vuln/detail/CVE-2021-23259
• https://docs.craftercms.org/en/3.1/security/advisory.html#cv-2021120102