WordPress through 4.7.4 relies on the Host HTTP header for a password-reset e-mail message, which makes it easier for remote attackers to reset arbitrary passwords by making a crafted wp-login.php?action=lostpassword request and then arranging for this message to bounce or be resent, leading to transmission of the reset key to a mailbox on an attacker-controlled SMTP server. This is related to problematic use of the SERVER_NAME variable in wp-includes/pluggable.php in conjunction with the PHP mail function. Exploitation is not achievable in all cases because it requires at least one of the following: (1) the attacker can prevent the victim from receiving any e-mail messages for an extended period of time (such as 5 days), (2) the victim's e-mail system sends an autoresponse containing the original message, or (3) the victim manually composes a reply containing the original message.

References

• https://nvd.nist.gov/vuln/detail/CVE-2017-8295
• https://exploitbox.io/vuln/WordPress-Exploit-4-7-Unauth-Password-Reset-0day-CVE-2017-8295.html
• https://wpvulndb.com/vulnerabilities/8807
• https://www.exploit-db.com/exploits/41963/
• http://www.debian.org/security/2017/dsa-3870
• http://www.securityfocus.com/bid/98295
• http://www.securitytracker.com/id/1038403