Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection')
Craft CMS is an open source content management system. In affected versions of Craft CMS an unrestricted file extension may lead to Remote Code Execution. If the name parameter value is not empty string('') in the View.php's doesTemplateExist() -> resolveTemplate() -> _resolveTemplateInternal() -> _resolveTemplate() function, it returns directly without extension verification, so that arbitrary extension files are rendered as twig templates. When attacker with admin privileges on a DEV or an improperly configured STG or PROD environment, they can exploit this vulnerability to remote code execution. Code execution may grant the attacker access to the host operating system. This issue has been addressed in version 4.4.6. Users are advised to upgrade. There are no known workarounds for this vulnerability.
All versions starting from 4.0.0 before 4.4.6
Upgrade to version 4.4.6 or above.