Astro-Shield is an integration to enhance website security with SubResource Integrity hashes, Content-Security-Policy headers, and other techniques. Versions from 1.2.0 to 1.3.1 of Astro-Shield allow bypass to the allow-lists for cross-origin resources by introducing valid `integrity` attributes to the injected code. This implies that the injected SRI hash would be added to the generated CSP header, which would lead the browser to believe that the injected resource is legit. This vulnerability is patched in version 1.3.2.

Astro-Shield is a library to compute the subresource integrity hashes for your JS scripts and CSS stylesheets. When automated CSP headers generation for SSR content is enabled and the web application serves content that can be partially controlled by external users, then it is possible that the CSP headers generation feature might be "allow-listing" malicious injected resources like inlined JS, or references to external malicious scripts. The fix is available in version 1.3.0.