Impact

The mailSend function in the default isMail transport in PHPMailer before 5.2.18 might allow remote attackers to pass extra parameters to the mail command and consequently execute arbitrary code via a " (backslash double quote) in a crafted Sender property.

Patches

Fixed in 5.2.18

Workarounds

Filter and validate user input before passing it to internal functions.

References

https://nvd.nist.gov/vuln/detail/CVE-2016-10033
Related to a follow-on issue in https://nvd.nist.gov/vuln/detail/CVE-2016-10045

For more information

If you have any questions or comments about this advisory:

• Open a private issue in the PHPMailer project

References

• GHSA-5f37-gxvh-23v6
• https://nvd.nist.gov/vuln/detail/CVE-2016-10033
• https://developer.joomla.org/security-centre/668-20161205-phpmailer-security-advisory.html
• https://github.com/FriendsOfPHP/security-advisories/blob/master/phpmailer/phpmailer/CVE-2016-10033.yaml
• https://github.com/PHPMailer/PHPMailer/releases/tag/v5.2.18
• https://github.com/PHPMailer/PHPMailer/wiki/About-the-CVE-2016-10033-and-CVE-2016-10045-vulnerabilities
• https://legalhackers.com/advisories/PHPMailer-Exploit-Remote-Code-Exec-CVE-2016-10033-Vuln.html
• https://www.drupal.org/psa-2016-004
• https://www.exploit-db.com/exploits/40968/
• https://www.exploit-db.com/exploits/40969/
• https://www.exploit-db.com/exploits/40970/
• https://www.exploit-db.com/exploits/40974/
• https://www.exploit-db.com/exploits/40986/
• https://www.exploit-db.com/exploits/41962/
• https://www.exploit-db.com/exploits/41996/
• https://www.exploit-db.com/exploits/42024/
• https://www.exploit-db.com/exploits/42221/
• http://packetstormsecurity.com/files/140291/PHPMailer-Remote-Code-Execution.html
• http://packetstormsecurity.com/files/140350/PHPMailer-Sendmail-Argument-Injection.html
• http://seclists.org/fulldisclosure/2016/Dec/78
• http://www.rapid7.com/db/modules/exploit/multi/http/phpmailer_arg_injection
• http://www.securityfocus.com/archive/1/539963/100/0/threaded
• http://www.securityfocus.com/bid/95108
• http://www.securitytracker.com/id/1037533