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.
{
"versions": [
{
"introduced": "1.5.0"
},
{
"last_affected": "3.6.5"
}
]
}