The wphttpvalidate_url function in wp-includes/http.php in WordPress before 4.4.2 allows remote attackers to conduct server-side request forgery (SSRF) attacks via a zero value in the first octet of an IPv4 address in the u parameter to wp-admin/press-this.php.
{
    "binaries": [
        {
            "binary_name": "wordpress",
            "binary_version": "4.4.2+dfsg-1"
        },
        {
            "binary_name": "wordpress-l10n",
            "binary_version": "4.4.2+dfsg-1"
        },
        {
            "binary_name": "wordpress-theme-twentyfifteen",
            "binary_version": "4.4.2+dfsg-1"
        },
        {
            "binary_name": "wordpress-theme-twentyfourteen",
            "binary_version": "4.4.2+dfsg-1"
        },
        {
            "binary_name": "wordpress-theme-twentysixteen",
            "binary_version": "4.4.2+dfsg-1"
        }
    ],
    "availability": "No subscription required"
}