The production web-site must filter unlisted file extensions in URL requests.

SV-32697r2_rule The production web-site must filter unlisted file extensions in URL requests.

Vulnerability discussion

Request filtering enables administrators to create a more granular rule set to allow or reject inbound web content. By setting limits on web requests it helps to ensure availability of web services and may also help mitigate the risk of buffer overflow type attacks. The allow unlisted property of the File Extensions Request Filter enables rejection of requests containing specific file extensions not defined in the File Extensions filter. Tripping this filter will cause IIS to generate a Status Code 404.7.

Check content

For each site reviewed: 1. Open the IIS Manager. 2. Click on the site name. 3. Double-click the Request Filtering icon. 4. Click Edit Feature Settings in the Actions Pane. If allow unlisted file extensions checkbox is checked, this is a finding.

Fix text

1. Open the IIS Manager. 2. Click the site name under review. 3. Double-click the Request Filtering icon. 4. Click Edit Feature Settings in the Actions Pane. 5. Uncheck the allow unlisted file extensions checkbox.

Pro Tips

Lavender hyperlinks in small type off to the right (of CSS class id, if you view the page source) point to globally unique URIs for each document and item. Copy the link location and paste anywhere you need to talk unambiguously about these things.

You can obtain data about documents and items in other formats. Simply provide an HTTP header Accept: text/turtle or Accept: application/rdf+xml.