^{CVE-2020-5615:}Cross-site request forgery vulnerability in PHP Factory Calendar products allows attackers to hijack administrator authentication.

Overview

The vulnerability affects PHP Factory's Calendar products, specifically [Calendar01] free edition ver1.0.0 and [Calendar02] free edition ver1.0.0. The CSRF vulnerability (CWE-352) allows attackers to create specially crafted web pages that, when visited by an authenticated administrator, can execute unauthorized actions on the calendar application. These actions would be performed with the administrator's privileges, potentially allowing attackers to modify calendar settings, add/delete events, or perform other administrative functions without authorization. This vulnerability poses a significant risk to the integrity and confidentiality of calendar data managed by these applications.

Remediation

To address this vulnerability, administrators should:

1. Update to the latest version of the Calendar01 and Calendar02 products if patches are available from PHP Factory.
2. Implement CSRF protection mechanisms if modifying the code yourself:
   • Add CSRF tokens to all forms and state-changing requests
   • Validate the origin and referrer headers for sensitive requests
   • Implement SameSite cookie attributes
3. Consider implementing additional security controls:
   • Use Content Security Policy (CSP) headers
   • Require re-authentication for sensitive operations
   • Implement proper session management
4. Monitor for suspicious activities that might indicate exploitation attempts
5. Consider temporarily disabling the vulnerable applications until patched versions are available if the risk is deemed too high

References

1. JVN Security Advisory: https://jvn.jp/en/jp/JVN73169744/index.html
2. PHP Factory Calendar01 Product Page: https://www.php-factory.net/calendar/01.php
3. PHP Factory Calendar02 Product Page: https://www.php-factory.net/calendar/02.php
4. OWASP CSRF Prevention Cheat Sheet: https://cheatsheetseries.owasp.org/cheatsheets/Cross-Site_Request_Forgery_Prevention_Cheat_Sheet.html
5. CWE-352: Cross-Site Request Forgery: https://cwe.mitre.org/data/definitions/352.html