^{CVE-2020-8134:}Server-side request forgery (SSRF) vulnerability in Ghost CMS versions prior to 3.10.0

Overview

This vulnerability affects Ghost CMS, a popular open-source publishing platform. The SSRF vulnerability allows attackers to make the Ghost CMS server perform HTTP requests to arbitrary destinations, including internal network resources that should not be accessible from the internet. By exploiting this vulnerability, attackers can potentially:

• Scan internal networks from the Ghost CMS server
• Access internal services and APIs
• Bypass network access controls and firewall restrictions
• Interact with cloud provider metadata services
• Potentially escalate attacks to retrieve sensitive information or gain further system access

The vulnerability is particularly dangerous in cloud environments where metadata services might expose sensitive configuration information or credentials.

Remediation

To remediate this vulnerability, take the following actions:

1. Update Ghost CMS to version 3.10.0 or later, which contains the security patch for this vulnerability.
2. If immediate updating is not possible, consider implementing additional network-level controls:
   • Restrict outbound connections from the Ghost CMS server
   • Implement a web application firewall (WAF) to filter potentially malicious requests
   • Use network segmentation to limit the Ghost CMS server's access to other internal systems
3. Monitor server logs for suspicious outbound connection attempts that might indicate exploitation attempts
4. Consider implementing additional SSRF protection mechanisms such as URL validation and whitelisting of allowed destinations for any server-initiated requests

References

1. HackerOne Report: https://hackerone.com/reports/793704 - Contains details about the vulnerability discovery and the patch implementation
2. CWE-918: https://cwe.mitre.org/data/definitions/918.html - Server-Side Request Forgery (SSRF) vulnerability classification
3. Ghost CMS Security Documentation: Check the official Ghost documentation for security updates and best practices
4. OWASP SSRF Prevention: https://cheatsheetseries.owasp.org/cheatsheets/Server_Side_Request_Forgery_Prevention_Cheat_Sheet.html - For general SSRF prevention techniques