CVE-2020-36326
Object injection in PHPMailer/PHPMailer
Summary
### Impact This is a reintroduction of an earlier issue (CVE-2018-19296) by an unrelated bug fix in PHPMailer 6.1.8. An external file may be unexpectedly executable if it is used as a path to an attachment file via PHP's support for `.phar` files. Exploitation requires that an attacker is able to provide an unfiltered path to a file to attach, or to trick calling code into generating one. See [this article](https://knasmueller.net/5-answers-about-php-phar-exploitation) for more info. ### Patches This issue was patched in the PHPMailer 6.4.1 release. This release also implements stricter filtering for attachment paths; paths that look like *any* kind of URL are rejected. ### Workarounds Validate paths to loaded files using the same pattern as used in [`isPermittedPath()`](https://github.com/PHPMailer/PHPMailer/blob/master/src/PHPMailer.php#L1815) before using them in *any* PHP file function, such as `file_exists`. This method can't be used directly because it is protected, but you can implement the same thing in calling code. Note that this should be applied to *all* user-supplied paths passed into such functions; it's not a problem specific to PHPMailer. ### Credit This issue was found by [Fariskhi Vidyan](https://github.com/farisv), reported and managed via Tidelift.
Affected packages
| Ecosystem | Package | Affected versions | Fixed versions |
|---|---|---|---|
| Packagist | phpmailer/phpmailer | — | 6.4.1 |
Remediation: Upgrade to 6.4.1 or later.
References
Includes data from the GitHub Advisory Database, licensed under CC-BY 4.0.
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EPSS scores provided by the FIRST.org Exploit Prediction Scoring System.