CVE-2021-3603

Ein entfernter, anonymer Angreifer kann mehrere Schwachstellen in PHPMailer ausnutzen, um beliebigen Programmcode auszuführen.

If a function is defined that has the same name as the default built-in email address validation scheme (`php`), it will be called in default configuration as when no validation scheme is provided, the default scheme's callable `php` was being called. If an attacker is able to inject such a function into the application (a much bigger issue), it will be called whenever an email address is validated, such as when calling `validateAddress()`. ### Impact Low impact – exploitation requires that an attacker can already inject code into an application, but it provides a trigger pathway. ### Patches This is patched in PHPMailer 6.5.0 by denying the use of simple strings as validator function names, which is a very minor BC break. ### Workarounds Inject your own email validator function. ### References Reported by [Vikrant Singh Chauhan](mailto:vi@hackberry.xyz) via [huntr.dev](https://www.huntr.dev/). [CVE-2021-3603](https://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2021-3603) ### For more information If you have any questions or comments about this advisory: * Open an issue in [the PHPMailer project](https://github.com/PHPMailer/PHPMailer) * [Email us](mailto:phpmailer@synchromedia.co.uk).

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.