CVE-2017-8295 in WordPress
Summary
by MITRE
WordPress through 4.7.4 relies on the Host HTTP header for a password-reset e-mail message, which makes it easier for user-assisted remote attackers to reset arbitrary passwords by making a crafted wp-login.php?action=lostpassword request and then arranging for this e-mail 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.
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Analysis
by VulDB Data Team • 01/11/2025
This vulnerability in WordPress versions through 4.7.4 represents a critical authentication bypass flaw that exploits the reliance on the HTTP Host header for password reset functionality. The issue stems from how WordPress processes the Host header in the wp-login.php?action=lostpassword endpoint, creating an opportunity for attackers to manipulate the email delivery process during password reset operations. The vulnerability specifically affects the wp-includes/pluggable.php file where the SERVER_NAME variable is improperly utilized in conjunction with the PHP mail function, leading to potential email spoofing scenarios.
The technical implementation of this flaw allows malicious actors to craft specially formatted requests to the password reset endpoint that can cause reset emails to be delivered to attacker-controlled mail servers rather than the legitimate user's email address. This occurs because the Host header value is directly incorporated into the email headers without proper validation or sanitization, enabling attackers to redirect password reset tokens to their own mail infrastructure. The vulnerability is particularly dangerous because it operates through a user-assisted attack vector where the victim must initiate the password reset process, but the attacker can influence the delivery mechanism through email bouncing or resending techniques.
From an operational impact perspective, this vulnerability creates a significant risk for WordPress installations as it enables unauthorized password resets without requiring authentication credentials. Attackers can exploit this weakness to gain access to user accounts by intercepting password reset tokens and redirecting them to their own email addresses. The attack requires minimal privileges and can be executed remotely, making it particularly dangerous for organizations with multiple user accounts. The vulnerability affects the core authentication mechanism of WordPress, potentially allowing attackers to compromise user sessions and access sensitive data within the WordPress environment.
The flaw aligns with CWE-200, which addresses information exposure through improper error handling, and can be categorized under ATT&CK technique T1213.002 for credential access through password reset mechanisms. Organizations should implement immediate mitigations including updating to WordPress version 4.7.5 or later, which addresses this vulnerability through proper validation of the Host header and email delivery mechanisms. Additional protective measures include implementing proper email header validation, monitoring for unusual password reset patterns, and configuring email servers to reject messages with suspicious routing information. The vulnerability demonstrates the importance of secure handling of HTTP headers and proper input validation in web applications, particularly when dealing with authentication and session management components.