CVE-2017-7234 in Django
Summary
by MITRE
A maliciously crafted URL to a Django (1.10 before 1.10.7, 1.9 before 1.9.13, and 1.8 before 1.8.18) site using the ``django.views.static.serve()`` view could redirect to any other domain, aka an open redirect vulnerability.
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Analysis
by VulDB Data Team • 11/27/2022
The vulnerability identified as CVE-2017-7234 represents a critical open redirect flaw within the Django web framework that affects multiple versions including 1.10 before 1.10.7, 1.9 before 1.9.13, and 1.8 before 1.8.18. This security issue stems from the improper handling of URLs within the django.views.static.serve() view function, which is commonly used to serve static files in Django applications. The flaw allows attackers to craft malicious URLs that can redirect users to arbitrary domains, potentially enabling phishing attacks, credential theft, or other malicious activities. The vulnerability specifically exploits the lack of proper input validation and URL sanitization in the static file serving mechanism.
The technical implementation of this vulnerability occurs when the django.views.static.serve() function processes a URL that contains a redirect parameter or malformed path that bypasses the intended security checks. This function typically handles static file serving by examining the requested path and serving files from the configured static directory. However, due to insufficient validation of the input parameters, particularly those related to redirect destinations, an attacker can manipulate the URL structure to force the application to redirect to a malicious domain. The flaw operates at the application layer and can be exploited through various means including crafted URLs in emails, web links, or through other social engineering techniques. This vulnerability falls under CWE-601 Open Redirect, which is categorized as a weakness in the input validation and output encoding of web applications. The issue aligns with ATT&CK technique T1566.001 Phishing, as it enables attackers to create convincing phishing campaigns by redirecting users to malicious domains through seemingly legitimate URLs.
The operational impact of CVE-2017-7234 extends beyond simple redirection attacks, as it can serve as a stepping stone for more sophisticated attacks within a broader exploitation chain. Organizations running affected Django versions are at risk of user deception attacks where legitimate-looking URLs can redirect to phishing sites designed to harvest credentials or install malware. The vulnerability can be particularly dangerous in enterprise environments where users may trust internal URLs or applications, making the redirect attack more convincing. Additionally, this flaw can be leveraged in cross-site scripting attacks or as part of a larger attack vector that combines multiple vulnerabilities to compromise user sessions or gain unauthorized access to sensitive resources. The open redirect capability also enables attackers to bypass security measures that rely on URL validation or domain checking mechanisms, potentially undermining the effectiveness of security tools and user awareness programs. Organizations should consider the broader security implications of this vulnerability, including potential damage to brand reputation and user trust when such redirects are successfully executed.
Mitigation strategies for CVE-2017-7234 primarily involve upgrading to patched versions of Django where the vulnerability has been addressed through proper input validation and URL sanitization. The recommended approach includes applying the official security patches released by the Django project for versions 1.8.18, 1.9.13, and 1.10.7, which contain fixes specifically designed to prevent unauthorized redirects in the static file serving functionality. Organizations should also implement additional defensive measures such as validating all redirect destinations against a whitelist of approved domains, implementing proper URL encoding and validation in application code, and monitoring for suspicious redirect patterns in web application logs. Network-level protections can include implementing web application firewalls that can detect and block malicious redirect attempts, while application-level controls should enforce strict validation of all URL parameters passed to the static serving views. Security teams should also conduct thorough vulnerability assessments to identify any custom implementations or third-party packages that might be using the vulnerable django.views.static.serve() function and ensure these components are properly updated or patched. The remediation process should include comprehensive testing to verify that the patched versions do not introduce regressions in legitimate static file serving functionality while effectively preventing the open redirect vulnerability.