The mail transport (aka Swift_Transport_MailTransport) in Swift Mailer before 5.4.5 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 e-mail address in the (1) From, (2) ReturnPath, or (3) Sender header.
packetstormsecurity.com/files/140290/SwiftMailer-Remote-Code-Execution.html
seclists.org/fulldisclosure/2016/Dec/86
www.debian.org/security/2017/dsa-3769
www.securityfocus.com/bid/95140
github.com/swiftmailer/swiftmailer/blob/5.x/CHANGES
legalhackers.com/advisories/SwiftMailer-Exploit-Remote-Code-Exec-CVE-2016-10074-Vuln.html
www.exploit-db.com/exploits/40972/
www.exploit-db.com/exploits/40986/
www.exploit-db.com/exploits/42221/