CVE-2016-10045 — The isMail transport in PHPMailer before 5

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 fun

01What is this vulnerability?

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.

02Affected products

Vendor	Product	Versions
n	a / n/a	n/a

03Active exploitation status

Not currently listed on the CISA Known Exploited Vulnerabilities (KEV) catalog. EPSS is the best forward-looking signal — see the EPSS row above.

04Recommended remediation

• Patch to a fixed version listed in the vendor advisory (see references below).
• Mitigate with WAF rules, network egress filters, or feature flags where the patch is not yet available.
• Hunt historical logs for exploitation indicators — see Detection signatures below.

05Technical details

For the full vendor write-up, exploit chains, and reference implementations, see the references list in section 09.

06Detection signatures

Open the Sigma generator with a pre-filled prompt for this CVE to draft a starting detection in your stack of choice:

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07Related CVEs

08Timeline

• Published: 2016-12-30T19:00:00.000Z
• Last modified: 2024-08-06T03:07:32.139Z

09References

• packetstormsecurity.com — http://packetstormsecurity.com/files/140286/PHPMailer-Remote-Code-Execution.html
• packetstormsecurity.com — http://packetstormsecurity.com/files/140350/PHPMailer-Sendmail-Argument-Injectio…
• www.exploit-db.com — https://www.exploit-db.com/exploits/42221/
• www.exploit-db.com — https://www.exploit-db.com/exploits/40969/
• www.securityfocus.com — http://www.securityfocus.com/archive/1/539967/100/0/threaded
• openwall.com — http://openwall.com/lists/oss-security/2016/12/28/1
• github.com — https://github.com/PHPMailer/PHPMailer/wiki/About-the-CVE-2016-10033-and-CVE-201…
• github.com — https://github.com/PHPMailer/PHPMailer/releases/tag/v5.2.20
• www.exploit-db.com — https://www.exploit-db.com/exploits/40986/
• www.rapid7.com — http://www.rapid7.com/db/modules/exploit/multi/http/phpmailer_arg_injection
• www.securityfocus.com — http://www.securityfocus.com/bid/95130
• legalhackers.com — https://legalhackers.com/advisories/PHPMailer-Exploit-Remote-Code-Exec-CVE-2016-…
• seclists.org — http://seclists.org/fulldisclosure/2016/Dec/81
• www.securitytracker.com — http://www.securitytracker.com/id/1037533
• developer.joomla.org — https://developer.joomla.org/security-centre/668-20161205-phpmailer-security-adv…