Description
parseWildcardRules in Gin-Gonic CORS middleware before 1.6.0 mishandles a wildcard at the end of an origin string, e.g., https://example.community/* is allowed when the intention is that only https://example.com/* should be allowed, and http://localhost.example.com/* is allowed when the intention is that only http://localhost/* should be allowed.
EPSS Score:
0%
Comprehensive Technical Analysis of EUVD-2024-1974
1. Vulnerability Assessment and Severity Evaluation
Vulnerability Description:
The vulnerability in question affects the parseWildcardRules function in the Gin-Gonic CORS middleware before version 1.6.0. This function mishandles wildcard characters at the end of origin strings, leading to unintended access permissions. Specifically, it allows broader access than intended, such as permitting https://example.community/* when only https://example.com/* should be allowed.
Severity Evaluation:
The vulnerability has a CVSS Base Score of 9.1, which is considered critical. The CVSS vector CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N indicates the following:
- Attack Vector (AV): Network (N)
- Attack Complexity (AC): Low (L)
- Privileges Required (PR): None (N)
- User Interaction (UI): None (N)
- Scope (S): Unchanged (U)
- Confidentiality (C): High (H)
- Integrity (I): High (H)
- Availability (A): None (N)
This high severity score underscores the potential for significant impact on confidentiality and integrity, making it a critical issue for immediate attention.
2. Potential Attack Vectors and Exploitation Methods
Attack Vectors:
- Unauthorized Access: An attacker could exploit this vulnerability to gain unauthorized access to resources by crafting origin strings that match the mishandled wildcard patterns.
- Data Exfiltration: By exploiting the vulnerability, an attacker could exfiltrate sensitive data from the affected application.
- Cross-Site Request Forgery (CSRF): The vulnerability could be used to perform CSRF attacks, where an attacker tricks a user into executing unwanted actions on a web application.
Exploitation Methods:
- Crafting Malicious Requests: An attacker could craft HTTP requests with origin headers that exploit the wildcard mishandling to bypass CORS restrictions.
- Phishing Attacks: An attacker could use phishing techniques to lure users into visiting malicious sites that exploit this vulnerability to gain unauthorized access.
3. Affected Systems and Software Versions
Affected Software:
- Gin-Gonic CORS middleware versions before 1.6.0
Affected Systems:
- Any web application or service that uses the affected versions of the Gin-Gonic CORS middleware.
4. Recommended Mitigation Strategies
Immediate Mitigation:
- Upgrade: Upgrade to Gin-Gonic CORS middleware version 1.6.0 or later, which includes the fix for this vulnerability.
- Temporary Workaround: Implement strict origin validation logic in the application code to manually enforce correct CORS policies until the upgrade is possible.
Long-Term Mitigation:
- Regular Audits: Conduct regular security audits and code reviews to identify and fix similar issues.
- Security Training: Provide training for developers on secure coding practices and the importance of proper CORS handling.
- Monitoring: Implement monitoring and alerting for unusual CORS-related activities to detect potential exploitation attempts.
5. Impact on European Cybersecurity Landscape
Regulatory Compliance:
- Organizations in the EU must comply with GDPR, which mandates strong data protection measures. This vulnerability could lead to data breaches, resulting in regulatory fines and reputational damage.
Cybersecurity Posture:
- The vulnerability highlights the importance of robust CORS handling in web applications. Organizations should prioritize securing their web applications to prevent unauthorized access and data breaches.
Collaboration and Sharing:
- The European cybersecurity community should collaborate and share information about such vulnerabilities to enhance collective defense mechanisms.
6. Technical Details for Security Professionals
Vulnerability Details:
- The
parseWildcardRulesfunction in the Gin-Gonic CORS middleware incorrectly processes wildcard characters at the end of origin strings, leading to broader access permissions than intended. - Example of incorrect handling:
https://example.community/*is allowed when the intention is that onlyhttps://example.com/*should be allowed.
Code Review:
- Review the
parseWildcardRulesfunction and ensure that wildcard characters are correctly interpreted and enforced. - Implement unit tests to validate the correct handling of wildcard characters in origin strings.
References:
Conclusion: The vulnerability in the Gin-Gonic CORS middleware is critical and requires immediate attention. Organizations should prioritize upgrading to the patched version and implement robust security measures to mitigate the risk of exploitation. Collaboration within the European cybersecurity community is essential to enhance overall defense mechanisms and ensure compliance with regulatory requirements.