CVE-2020-26251 Explained : Impact and Mitigation
Learn about CVE-2020-26251 affecting Open Zaak versions before 1.3.3. Understand the impact, technical details, and mitigation steps for this CORS configuration vulnerability.
Open Zaak is a modern, open-source data- and services-layer enabling zaakgericht werken. The vulnerability in versions prior to 1.3.3 allows for potential Cross-Origin-Resource-Sharing (CORS) policy exploitation.
Understanding CVE-2020-26251
This CVE addresses a vulnerability in Open Zaak versions before 1.3.3 that could potentially expose installations to Cross-Origin-Resource-Sharing (CORS) policy issues.
What is CVE-2020-26251?
Open Zaak versions prior to 1.3.3 have a wide-open CORS policy, allowing any client to access the system. While the vulnerability theoretically exists, several mitigating factors make exploitation unlikely.
The Impact of CVE-2020-26251
The vulnerability has a CVSS base score of 4.7, indicating a medium severity issue. However, due to various security measures in place, the actual exploitability is limited.
Technical Details of CVE-2020-26251
This section delves into the specific technical aspects of the vulnerability.
Vulnerability Description
The CORS policy in Open Zaak versions before 1.3.3 is overly permissive, potentially allowing unauthorized access to the system.
Affected Systems and Versions
- Product: open-zaak
- Vendor: open-zaak
- Versions Affected: < 1.3.3
Exploitation Mechanism
The vulnerability arises from the wide-open CORS policy, which could be exploited by malicious actors to perform AJAX calls to Open Zaak installations.
Mitigation and Prevention
To address and prevent the exploitation of this vulnerability, certain steps can be taken.
Immediate Steps to Take
- Upgrade Open Zaak to version 1.3.3 or higher to disable CORS by default.
- Ensure proper configuration of environment variables to opt-in CORS if necessary.
Long-Term Security Practices
- Regularly review and update CORS policies to align with security best practices.
- Implement strict access controls and authentication mechanisms to protect sensitive data.
Patching and Updates
- Stay informed about security advisories and updates from Open Zaak.
- Apply patches promptly to mitigate known vulnerabilities.