Svelte 3.3.0 is a minor release of the Svelte JavaScript framework, building upon version 3.2.2. Both versions share the same core philosophy of "cybernetically enhanced web apps," offering a compiler-driven approach to building performant and reactive user interfaces. Examining the package data, the primary difference lies in the release dates and associated changes within the framework itself. Version 3.3.0 was released on May 13, 2019, a few days after version 3.2.2, released on May 9, 2019, suggesting bug fixes, minor feature enhancements, or performance improvements were the focus of the newer version.
A close comparison of the devDependencies reveals no explicit changes in the dependencies between the two. This indicates that the development environment and tooling used for building Svelte remained consistent across these versions. Developers utilizing Svelte should appreciate the stability in the build process. While the tools didn't change, the internal refinements and possible bug fixes introduced in 3.3.0 contribute to an overall improved and more reliable experience compared to 3.2.2. Furthermore, both packages maintain the same license (MIT), repository, and author (Rich Harris), underlining the continuity and open-source nature of the project. The slight difference in unpacked size suggests that the newer version might contain tweaked code or assets; however the core building and usage of the library remains relatively unchanged. Developers are always encouraged to use the latest stable version for the best performance and reliability.
All the vulnerabilities related to the version 3.3.0 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