CVE-2015-8474 in Redmine
Summary
by MITRE
Open redirect vulnerability in the valid_back_url function in app/controllers/application_controller.rb in Redmine before 2.6.7, 3.0.x before 3.0.5, and 3.1.x before 3.1.1 allows remote attackers to redirect users to arbitrary web sites and conduct phishing attacks via a crafted back_url parameter, as demonstrated by "@attacker.com," a different vulnerability than CVE-2014-1985.
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Analysis
by VulDB Data Team • 07/13/2022
The CVE-2015-8474 vulnerability represents a critical open redirect flaw within the Redmine project management platform that affects multiple version ranges including 2.6.6 and earlier, 3.0.4 and earlier, and 3.1.0 and earlier releases. This vulnerability resides in the application_controller.rb file within the valid_back_url function, which is responsible for handling user navigation redirects after authentication or other operations. The flaw enables remote attackers to manipulate the back_url parameter and redirect users to malicious websites, creating a significant security risk for organizations relying on Redmine for project management and collaboration.
The technical implementation of this vulnerability stems from inadequate input validation and sanitization within the redirect handling mechanism. When users navigate through Redmine's authentication flow or perform certain operations, the application constructs redirect URLs based on the back_url parameter provided by the user. The vulnerable code fails to properly validate or sanitize this parameter, allowing attackers to inject malicious URLs that bypass normal security checks. This particular flaw differs from CVE-2014-1985, which addressed a similar but distinct vulnerability in Redmine's redirect handling, demonstrating that the software development team had previously identified and addressed open redirect issues but failed to completely resolve the problem.
The operational impact of CVE-2015-8474 extends beyond simple redirection attacks, creating significant risks for phishing campaigns and social engineering operations. Attackers can craft malicious URLs that appear legitimate to users, leveraging the trusted Redmine domain to redirect victims to attacker-controlled sites designed to capture credentials or install malware. The vulnerability is particularly dangerous because it can be exploited through various attack vectors including email phishing, compromised links in forums, or malicious web applications that interact with Redmine. Organizations using vulnerable versions of Redmine face potential data breaches, credential theft, and reputational damage when attackers successfully exploit this flaw.
Security practitioners should implement immediate mitigations including upgrading to patched versions of Redmine, specifically versions 2.6.7, 3.0.5, and 3.1.1, which contain the necessary fixes for this vulnerability. The remediation process should also include implementing proper input validation for all redirect parameters and establishing a whitelist of acceptable redirect URLs to prevent unauthorized redirection. Organizations should conduct comprehensive security assessments to identify any potential exploitation attempts and monitor network traffic for suspicious redirect patterns. Additionally, user education regarding phishing awareness becomes crucial, as the vulnerability relies heavily on social engineering to succeed in redirecting users to malicious sites. This vulnerability aligns with CWE-601 open redirect weakness classification and represents a technique commonly used in the ATT&CK framework under the Initial Access and Credential Access phases, specifically targeting the use of malicious redirects for credential harvesting.
The broader implications of this vulnerability highlight the importance of proper input validation in web applications and the necessity of maintaining up-to-date security patches. Organizations should establish robust patch management processes to ensure timely deployment of security fixes and implement security monitoring to detect potential exploitation attempts. The vulnerability also underscores the need for comprehensive security testing including penetration testing and code reviews to identify similar issues in other applications. Regular security assessments and vulnerability scanning should be integrated into the development lifecycle to prevent similar flaws from reaching production environments, particularly in applications handling user authentication and navigation flows.