CVE-2019-25211
CVE-2019-25211
Weakness (CWE)
CVSS Vector
v3.1- Attack Vector
- Network
- Attack Complexity
- Low
- Privileges Required
- None
- User Interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- None
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.
Comprehensive Technical Analysis of CVE-2019-25211
1. Vulnerability Assessment and Severity Evaluation
CVE ID: CVE-2019-25211
Description: The vulnerability affects the parseWildcardRules function in the Gin-Gonic CORS middleware before version 1.6.0. The issue arises from the mishandling of wildcard characters at the end of origin strings. This misconfiguration allows broader access than intended, potentially exposing sensitive resources to unauthorized access.
CVSS Score: 9.1
Severity Evaluation:
- Confidentiality Impact: High
- Integrity Impact: High
- Availability Impact: High
The high CVSS score of 9.1 indicates a critical vulnerability that could lead to significant security risks if exploited. The misconfiguration can allow unauthorized access to resources, leading to potential data breaches, unauthorized modifications, and service disruptions.
2. Potential Attack Vectors and Exploitation Methods
Attack Vectors:
- Unauthorized Access: An attacker could exploit the wildcard misconfiguration to gain access to resources that should be restricted. For example, an attacker could use
https://example.community/*to access resources intended only forhttps://example.com/*. - Cross-Site Request Forgery (CSRF): The vulnerability could be leveraged to perform CSRF attacks, where an attacker tricks a user into executing unwanted actions on a web application in which they're authenticated.
- Data Exfiltration: Unauthorized access could lead to data exfiltration, where sensitive information is extracted from the compromised system.
Exploitation Methods:
- Manipulating Origin Strings: Attackers can manipulate origin strings to include wildcards that match broader patterns than intended, thereby gaining unauthorized access.
- Phishing and Social Engineering: Attackers could use phishing techniques to trick users into visiting malicious sites that exploit this vulnerability.
3. Affected Systems and Software Versions
Affected Software:
- Gin-Gonic CORS middleware versions before 1.6.0
Systems at Risk:
- Any web application or service using the affected versions of the Gin-Gonic CORS middleware.
- Systems that rely on strict CORS policies to enforce security boundaries.
4. Recommended Mitigation Strategies
Immediate Actions:
- Upgrade to Version 1.6.0 or Later: Ensure that all instances of the Gin-Gonic CORS middleware are updated to version 1.6.0 or later, which includes the fix for this vulnerability.
- Review and Validate CORS Policies: Conduct a thorough review of CORS policies to ensure they are correctly configured and do not inadvertently allow broader access than intended.
Long-Term Strategies:
- Regular Security Audits: Implement regular security audits to identify and mitigate similar vulnerabilities.
- Automated Patch Management: Use automated tools to ensure that all software dependencies are kept up-to-date with the latest security patches.
- Security Training: Provide training for developers and administrators on secure coding practices and configuration management.
5. Impact on Cybersecurity Landscape
Broader Implications:
- Increased Risk of Data Breaches: The vulnerability highlights the importance of proper configuration management in preventing data breaches and unauthorized access.
- Need for Robust CORS Policies: Organizations must ensure that CORS policies are robust and correctly implemented to prevent similar vulnerabilities.
- Emphasis on Regular Updates: The incident underscores the necessity of regular updates and patch management to mitigate known vulnerabilities.
6. Technical Details for Security Professionals
Technical Analysis:
- Root Cause: The root cause of the vulnerability is the improper handling of wildcard characters in the
parseWildcardRulesfunction. The function does not correctly interpret the wildcard at the end of the origin string, leading to broader access permissions. - Code Review: A detailed code review of the
parseWildcardRulesfunction in versions before 1.6.0 reveals that the wildcard handling logic is flawed. The fix in version 1.6.0 addresses this by ensuring that wildcards are correctly interpreted and restricted. - Testing and Validation: Security professionals should conduct thorough testing to validate that the updated CORS middleware correctly enforces the intended access controls. This includes both automated and manual testing to ensure that wildcards are handled appropriately.
References:
By addressing this vulnerability promptly and implementing robust security practices, organizations can significantly reduce the risk of unauthorized access and data breaches.