Authenticated users with Administrator or Developer roles may execute OS commands by SPEL Expression in Spring beans. SPEL Expression does not have security restrictions, which will cause attackers to execute arbitrary commands remotely (RCE).

References

• https://nvd.nist.gov/vuln/detail/CVE-2021-23258
• https://docs.craftercms.org/en/3.1/security/advisory.html#cv-2021120101