CVE-2020-9309 : Exploit Details and Defense Strategies

Silverstripe CMS through 4.5 is vulnerable to script execution from malicious upload contents under allowed file extensions, potentially leading to browser execution of file contents.

Understanding CVE-2020-9309

What is CVE-2020-9309?

Silverstripe CMS through version 4.5 is at risk of allowing script execution from malicious upload contents under permitted file extensions, potentially leading to the execution of file contents by browsers.

The Impact of CVE-2020-9309

This vulnerability could be exploited by attackers to execute malicious scripts through uploaded files, posing a risk of unauthorized code execution and potential compromise of the affected system.

Technical Details of CVE-2020-9309

Vulnerability Description

Silverstripe CMS through version 4.5 allows script execution from malicious upload contents under permitted file extensions.

Affected Systems and Versions

Product: Not applicable
Vendor: Not applicable
Versions: Not applicable

Exploitation Mechanism

Malicious upload contents under allowed file extensions can trigger script execution, potentially leading to browser execution of file contents.

Mitigation and Prevention

Immediate Steps to Take

Ensure authorized users only upload files stored as protected or draft files.
Disable the option for custom logic or modules like silverstripe/userforms to enable uploads as protected or draft files.

Long-Term Security Practices

Regularly review and update file upload policies and restrictions.
Implement strict MIME whitelists to prevent unauthorized file execution.

Patching and Updates

Update to the latest version of Silverstripe CMS to mitigate this vulnerability.