CVE-2016-10033
PHPMailer Command Injection
- Published30 Dec 2016
- Added to CISA KEV7 Jul 2025
- Remediation due28 Jul 2025
Description
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.
CVSS 3.1 breakdown
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HAffected products
Remediation
- http://seclists.org/fulldisclosure/2016/Dec/78
- 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.exploit-db.com/exploits/40968/
- https://www.exploit-db.com/exploits/40970/
References
- http://packetstormsecurity.com/files/140291/PHPMailer-Remote-Code-Execution.html
- http://packetstormsecurity.com/files/140350/PHPMailer-Sendmail-Argument-Injection.html
- https://developer.joomla.org/security-centre/668-20161205-phpmailer-security-advisory.html
- http://seclists.org/fulldisclosure/2016/Dec/78
- 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.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2016-10033
- https://www.drupal.org/psa-2016-004
- https://www.exploit-db.com/exploits/40968/
and 12 more references
Related CVEs
Recent high-severity vulnerabilities sharing a weakness type.
Frequently asked
Is CVE-2016-10033 being actively exploited?
Yes. CVE-2016-10033 is listed in the CISA Known Exploited Vulnerabilities (KEV) catalog, added 7 Jul 2025.
How severe is CVE-2016-10033?
CVE-2016-10033 has a CVSS 3.1 base score of 9.8, rated critical. EPSS estimates a 99.7% probability of exploitation.
Which products are affected by CVE-2016-10033?
Affected products include Joomla Joomla!, Phpmailer, WordPress.
How do I fix CVE-2016-10033?
Upgrade affected software to a fixed version, for example Phpmailer 5.2.18 or later, then confirm no affected versions remain in your inventory.
How Secuno handles this
Secuno correlates vulnerabilities like CVE-2016-10033 against the real software inventory on every managed device, every day. Rather than a static severity, each match is scored in context: exploit availability, EPSS, the asset's exposure, and business criticality decide where it lands in the queue. Because it is on the CISA KEV list, Secuno flags any affected asset as top-priority automatically. If an affected version is present anywhere across your portfolio, it surfaces automatically with a prioritised remediation path.
Data from the NVD, CISA KEV catalog and FIRST EPSS. CVSS 3.1 base score shown where available.