CVE-2017-9303 in Laravel
Summary
by MITRE
Laravel 5.4.x before 5.4.22 does not properly constrain the host portion of a password-reset URL, which makes it easier for remote attackers to conduct phishing attacks by specifying an attacker-controlled host.
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Analysis
by VulDB Data Team • 05/30/2017
The vulnerability identified as CVE-2017-9303 affects Laravel framework versions 5.4.x prior to 5.4.22 and represents a significant security flaw in the password reset functionality. This issue stems from improper validation of the host portion within password reset URLs, creating an avenue for attackers to manipulate the domain component of these critical links. The flaw enables malicious actors to craft deceptive password reset emails that appear to originate from legitimate domains while actually directing users to attacker-controlled servers.
The technical implementation of this vulnerability lies in how Laravel handles the generation and validation of password reset tokens within URL structures. When a user requests a password reset, the system generates a URL containing a token that allows account recovery. However, the framework failed to properly constrain or validate the host portion of this URL, allowing attackers to substitute their own domain in the reset link. This occurs during the email generation process where the application constructs the reset URL without sufficient host validation, enabling arbitrary domain substitution in the generated links.
The operational impact of this vulnerability extends beyond simple phishing attacks, creating a comprehensive threat vector that can be exploited across multiple attack scenarios. Attackers can craft convincing password reset emails that appear authentic to users, potentially leading to credential theft and unauthorized account access. The vulnerability is particularly dangerous because it operates at the application level rather than network level, making it harder to detect through traditional network monitoring approaches. This weakness enables sophisticated social engineering campaigns where attackers can create highly convincing fake reset pages that closely mimic legitimate authentication interfaces.
From a threat modeling perspective, this vulnerability aligns with several ATT&CK framework techniques including initial access through phishing, credential access via phishing, and privilege escalation through account takeover. The vulnerability maps to CWE-601 which specifically addresses URL redirection and forwarding vulnerabilities, where the flaw creates an unvalidated redirect that can lead to user deception and credential compromise. The issue also relates to CWE-20 which covers input validation errors, as the system fails to properly validate the host portion of URLs before incorporating them into generated links. Organizations using affected Laravel versions face increased risk of successful credential theft campaigns, particularly when users are targeted through spear-phishing or broad-based attacks.
The recommended mitigation strategy involves upgrading to Laravel version 5.4.22 or later, which includes proper host validation for password reset URLs. Additionally, security teams should implement comprehensive email authentication measures including dkim, spf, and dmarc to help users identify legitimate communications. Organizations should also consider implementing additional verification steps for password reset requests, such as requiring secondary authentication methods or sending reset notifications to registered email addresses. Network monitoring should be enhanced to detect unusual patterns in password reset email traffic, and user education programs should emphasize the importance of verifying the authenticity of reset links before clicking. The vulnerability serves as a reminder of the critical importance of validating all user-supplied input and ensuring that application-generated URLs maintain proper integrity controls to prevent malicious manipulation.