PHPMailer < 5.2.18 Remote Code Execution [CVE-2016-10033] Severity: CRITICAL Discovered by: Dawid Golunski (@dawid_golunski) https://legalhackers.com PHPMailer "Probably the world's most popular code for sending email from PHP! Used by many open-source projects: WordPress, Drupal, 1CRM, SugarCRM, Yii, Joomla! and many more" Desc: An independent research uncovered a critical vulnerability in PHPMailer that could potentially be used by (unauthenticated) remote attackers to achieve remote arbitrary code execution in the context of the web server user and remotely compromise the target web application. To exploit the vulnerability an attacker could target common website components such as contact/feedback forms, registration forms, password email resets and others that send out emails with the help of a vulnerable version of the PHPMailer class. Patching: Responsibly disclosed to PHPMailer team. They've released a critical security release. If you are using an affected release update to the 5.2.18 security release as advised at: https://github.com/PHPMailer/PHPMailer/blob/master/changelog.md Notes: I know this is a bad timing and a short notice (for everyone probably ;) I've spent most of my Christmas break working on this issue with affected vendors. This has been quite a rush as one of the vendors leaked excessive information on this vulnerability at one point which could aid potential attackers. I've released a limited advisory at the link below: https://legalhackers.com/advisories/PHPMailer-Exploit-Remote-Code-Exec-CVE-2016-10033-Vuln.html This is to give people a chance to immediately patch or at least be aware of the issue before we get closer to a working day/end of holiday for affected users to act on this issue. I'm planning to release the full advisory and a PoC exploit shortly so that everyone is on the same page. Upcoming video PoC: https://legalhackers.com/videos/PHPMailer-Exploit-Remote-Code-Exec-Vuln-CVE-2016-10033-PoC.html For updates follow: https://twitter.com/dawid_golunski I'll also send another email to the list once it is published. For now, Patch it now before someone else patches it for you (through a reverse shell ;) -- Regards, Dawid Golunski https://legalhackers.com t: @dawid_golunski