# CVE-2016-10033

The mailSend function in the 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.

- Page: https://www.vulneraibility.com/cve/CVE-2016-10033
- CVSS: 9.8
- Known exploited: yes, in CISA KEV since 2025-07-07; CISA due date 2025-07-28
- EPSS: 99.71%
- Public exploit code: 9 on Exploit-DB · 2 Metasploit modules · 17 GitHub proofs of concept · 1 Nuclei template (first 2016-12-25)
- CISA SSVC: exploitation active, automatable yes, technical impact total (assessed 2025-07-17)
- Weakness: CWE-88
- Also known as: GHSA-5f37-gxvh-23v6
- Published: 2016-12-30

## Affected

- phpmailer_project:phpmailer
- wordpress:wordpress
- joomla:joomla\!

## References

- [other] http://packetstormsecurity.com/files/140350/PHPMailer-Sendmail-Argument-Injection.html
- [other] https://www.drupal.org/psa-2016-004
- [exploit] https://www.exploit-db.com/exploits/42221/
- [exploit] https://www.exploit-db.com/exploits/40969/
- [exploit] https://www.exploit-db.com/exploits/41962/
- [exploit] https://www.exploit-db.com/exploits/40968/
- [other] https://legalhackers.com/advisories/PHPMailer-Exploit-Remote-Code-Exec-CVE-2016-10033-Vuln.html
- [other] https://github.com/PHPMailer/PHPMailer/releases/tag/v5.2.18
- [other] http://www.securityfocus.com/archive/1/539963/100/0/threaded
- [other] https://github.com/PHPMailer/PHPMailer/wiki/About-the-CVE-2016-10033-and-CVE-2016-10045-vulnerabilities
- [other] http://packetstormsecurity.com/files/140291/PHPMailer-Remote-Code-Execution.html
- [exploit] https://www.exploit-db.com/exploits/40974/
- [exploit] https://www.exploit-db.com/exploits/40986/
- [exploit] https://www.exploit-db.com/exploits/40970/
- [other] http://www.rapid7.com/db/modules/exploit/multi/http/phpmailer_arg_injection
- [exploit] https://www.exploit-db.com/exploits/41996/
- [other] http://seclists.org/fulldisclosure/2016/Dec/78
- [other] http://www.securityfocus.com/bid/95108
- [other] http://www.securitytracker.com/id/1037533
- [other] https://developer.joomla.org/security-centre/668-20161205-phpmailer-security-advisory.html
- [exploit] https://www.exploit-db.com/exploits/42024/
- [other] https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2016-10033

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Summary, impact and action are written by the vulneraibility.com AI analysis pipeline from the CVE record, NVD, CISA and FIRST data; verify against the references.