Svelte 3.30.0 represents a subtle but important update over its predecessor, version 3.29.7 in the Svelte framework. Both versions share the same core mission: to provide developers with a "cybernetically enhanced" approach to building web applications. The descriptions, license, repository information, and author remain consistent, indicating a continuation of the project's established principles and maintainership.
The key differences lie in the details. The file count within the distributed package increases slightly from 212 to 213, and unpacked size grows notably from 6001546 bytes to 6249458 bytes. This suggests that Svelte 3.30.0 includes new features, bug fixes, or performance improvements that warrant a larger package size. While the devDependencies remain mostly consistent, any internal tweaks or updated dependencies could contribute.
For developers, this means upgrading to Svelte 3.30.0 likely brings a refined development experience. The increased package size points towards potential enhancements in areas such as compiler optimizations, improved runtime performance, or the addition of new features that simplify common development tasks. While the changes aren't drastic, staying up-to-date ensures developers benefit from the latest advancements, security patches, and bug fixes within the Svelte ecosystem, leading to more efficient and robust web application development. Finally, the release date of November 24, 2020 versus November 10, 2020 indicates a relatively short development cycle between the two versions.
All the vulnerabilities related to the version 3.30.0 of the package
Svelte vulnerable to XSS when using objects during server-side rendering
The package svelte before 3.49.0 is vulnerable to Cross-site Scripting (XSS) due to improper input sanitization and to improper escape of attributes when using objects during SSR (Server-Side Rendering). Exploiting this vulnerability is possible via objects with a custom toString() function.
Svelte has a potential mXSS vulnerability due to improper HTML escaping
A potential XSS vulnerability exists in Svelte for versions prior to 4.2.19.
Svelte improperly escapes HTML on server-side rendering. It converts strings according to the following rules:
" -> "& -> &< -> <& -> &The assumption is that attributes will always stay as such, but in some situation the final DOM tree rendered on browsers is different from what Svelte expects on server-side rendering. This may be leveraged to perform XSS attacks. More specifically, this can occur when injecting malicious content into an attribute within a <noscript> tag.
A vulnerable page (+page.svelte):
<script>
import { page } from "$app/stores"
// user input
let href = $page.url.searchParams.get("href") ?? "https://example.com";
</script>
<noscript>
<a href={href}>test</a>
</noscript>
If a user accesses the following URL,
http://localhost:4173/?href=</noscript><script>alert(123)</script>
then, alert(123) will be executed.
XSS, when using an attribute within a noscript tag