Remote code execution in PHPMailer

CRITIQUE 9.8CVE-2016-10045 · GHSA-4pc3-96mx-wwc8 · Published 30/12/2016 · updated 17/06/2026

Package	Affected versions	Patched versions
phpmailer/phpmailer Packagist	`≥ 5.0.0, < 5.2.20`	`5.2.20`
joomla! joomla	`≥ 1.5.0, ≤ 3.6.5`	No fix yet
phpmailer phpmailer_project	`< 5.2.20`	`5.2.20`
wordpress wordpress	`≤ 4.7`	No fix yet

Description

Impact

The isMail transport in PHPMailer before 5.2.20 might allow remote attackers to pass extra parameters to the mail command and consequently execute arbitrary code by leveraging improper interaction between the escapeshellarg function and internal escaping performed in the mail function in PHP. NOTE: this vulnerability exists because of an incorrect fix for CVE-2016-10033.

This issue really emphasises that it's worth avoiding the built-in PHP mail() function entirely.

Patches

Fixed in 5.2.20

Workarounds

Send via SMTP to localhost instead of calling the mail() function.

References

https://nvd.nist.gov/vuln/detail/CVE-2016-10045 See also https://nvd.nist.gov/vuln/detail/CVE-2016-10033

For more information

If you have any questions or comments about this advisory:

Open a private issue in the PHPMailer project

NVD description

The isMail transport in PHPMailer before 5.2.20 might allow remote attackers to pass extra parameters to the mail command and consequently execute arbitrary code by leveraging improper interaction between the escapeshellarg function and internal escaping performed in the mail function in PHP. NOTE: this vulnerability exists because of an incorrect fix for CVE-2016-10033.

References

PHPMailer/PHPMailer security advisory · WEB
nvd.nist.gov/vuln/detail/CVE-2016-10045 · ADVISORY
developer.joomla.org/security-centre/668-20161205-phpmailer-security-advisory.html · WEB
FriendsOfPHP/security-advisories · WEB
PHPMailer/PHPMailer · PACKAGE
PHPMailer/PHPMailer release v5.2.20 · WEB
PHPMailer/PHPMailer · WEB
legalhackers.com/advisories/PHPMailer-Exploit-Remote-Code-Exec-CVE-2016-10045-Vuln-Patch-Bypass.html · WEB
exploit-db.com/exploits/40969 · WEB
exploit-db.com/exploits/40986 · WEB
exploit-db.com/exploits/42221 · WEB
openwall.com/lists/oss-security/2016/12/28/1 · WEB
packetstormsecurity.com/files/140286/PHPMailer-Remote-Code-Execution.html · WEB
packetstormsecurity.com/files/140350/PHPMailer-Sendmail-Argument-Injection.html · WEB
seclists.org/fulldisclosure/2016/Dec/81 · WEB
rapid7.com/db/modules/exploit/multi/http/phpmailer_arg_injection · WEB
securityfocus.com/archive/1/539967/100/0/threaded · Third Party Advisory
securityfocus.com/bid/95130 · Exploit
securitytracker.com/id/1037533 · Third Party Advisory
exploit-db.com/exploits/40969 · Exploit
exploit-db.com/exploits/40986 · Third Party Advisory
exploit-db.com/exploits/42221 · Third Party Advisory

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