### [CVE-2021-3603](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-3603) ![](https://img.shields.io/static/v1?label=Product&message=PHPMailer&color=blue) ![](https://img.shields.io/static/v1?label=Version&message=unspecified%20&color=brightgreen) ![](https://img.shields.io/static/v1?label=Vulnerability&message=CWE-829%20Inclusion%20of%20Functionality%20from%20Untrusted%20Control%20Sphere&color=brightgreen) ### Description PHPMailer 6.4.1 and earlier contain a vulnerability that can result in untrusted code being called (if such code is injected into the host project's scope by other means). If the $patternselect parameter to validateAddress() is set to 'php' (the default, defined by PHPMailer::$validator), and the global namespace contains a function called php, it will be called in preference to the built-in validator of the same name. Mitigated in PHPMailer 6.5.0 by denying the use of simple strings as validator function names. ### POC #### Reference - https://www.huntr.dev/bounties/1-PHPMailer/PHPMailer/ #### Github - https://github.com/ARPSyndicate/cvemon - https://github.com/KatenKyoukotsu/devsecops - https://github.com/qquang/CTFs