#VU3118 Remote code injection in PHPMailer - CVE-2016-10033

Vulnerability identifier: #VU3118

Vulnerability risk: High

CVSSv4.0: 9.3 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:A/U:Amber]

CVE-ID: CVE-2016-10033

CWE-ID: CWE-94

Exploitation vector: Network

Exploit availability: Yes

Vulnerable software:
PHPMailer
Web applications / Other software

Vendor: phpmailer.sourceforge.net

Description

The vulnerability allows a remote attacker to execute arbitrary code on the target system.

The vulnerability exists due to insufficient sanitization of user-supplied input passed via specially crafted “From” address to mailSend() function. A remote attacker can use backslashed double quote character (e.g. \") to pass additional commands to original mail command and execute them with privileges of the current web server user.

Successful exploitation of the vulnerability may result in system compromise.

Mitigation
Install the latest version 5.2.21 from vendor's website.

Vulnerable software versions

PHPMailer: 5.2.2 - 5.2.17

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External links
https://packetstormsecurity.com/files/140291/PHPMailer-Remote-Code-Execution.html
https://seclists.org/fulldisclosure/2016/Dec/78
https://www.securityfocus.com/archive/1/archive/1/539963/100/0/threaded
https://www.securityfocus.com/bid/95108
https://developer.joomla.org/security-centre/668-20161205-phpmailer-security-advisory.html
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-vulnerabilit...
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/40970/

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Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability. However, a fully functional exploit for this vulnerability is available.