CVE-2017-11173 : Security Advisory and Response
Learn about CVE-2017-11173, a critical vulnerability in rack-cors versions prior to 0.4.1 allowing malicious third-party sites to execute CORS requests. Find out the impact, affected systems, and mitigation steps.
CVE-2017-11173 was published on July 13, 2017, and affects rack-cors versions prior to 0.4.1. This vulnerability allows malicious third-party websites to execute Cross-Origin Resource Sharing (CORS) requests, potentially leading to security breaches.
Understanding CVE-2017-11173
This CVE highlights a critical issue in the rack-cors library that could be exploited by attackers to bypass intended domain restrictions.
What is CVE-2017-11173?
The absence of an anchor in the generated regex for rack-cors before version 0.4.1 creates a vulnerability that allows malicious third-party websites to perform CORS requests. This oversight can inadvertently permit unauthorized domains to access resources.
The Impact of CVE-2017-11173
The vulnerability in rack-cors could lead to a scenario where a trusted domain, such as example.com, inadvertently allows access to a malicious domain like example.com.example.net, compromising security measures.
Technical Details of CVE-2017-11173
This section delves into the specifics of the vulnerability, including affected systems, exploitation mechanisms, and mitigation strategies.
Vulnerability Description
The missing anchor in the regex of rack-cors versions prior to 0.4.1 enables unauthorized domains to bypass CORS restrictions, potentially leading to unauthorized data access.
Affected Systems and Versions
- Product: Not applicable
- Vendor: Not applicable
- Versions affected: All versions before 0.4.1
Exploitation Mechanism
Attackers can exploit this vulnerability by crafting URLs that combine trusted and malicious domain names, tricking the system into allowing unauthorized CORS requests.
Mitigation and Prevention
Protecting systems from CVE-2017-11173 requires immediate actions and long-term security practices.
Immediate Steps to Take
- Upgrade rack-cors to version 0.4.1 or newer to patch the vulnerability.
- Review and update CORS configurations to ensure proper domain restrictions.
Long-Term Security Practices
- Regularly monitor and update libraries and dependencies to address security flaws promptly.
- Conduct security audits to identify and mitigate CORS-related vulnerabilities.
Patching and Updates
- Stay informed about security advisories and patches released by the rack-cors maintainers.
- Implement a robust patch management process to apply updates promptly and effectively.