Svelte 3.17.2 is a minor update to the Svelte JavaScript compiler, building upon the solid foundation of version 3.17.1. Both versions share the same core purpose: crafting cybernetically enhanced web applications with exceptional performance and a streamlined developer experience. The primary difference lies in the updated code-red dev dependency, moving from version 0.0.28 to 0.0.31. While seemingly minor, this update within the development tools could introduce subtle improvements or bug fixes that indirectly benefit developers through a more robust build process or potentially impacting the compiled output in nuanced ways.
For developers considering integrating or upgrading to Svelte, the core benefits remain consistent between these versions. Svelte distinguishes itself by shifting the workload from the browser to the compile step. This results in smaller, faster, and more efficient JavaScript bundles, leading to improved application load times and responsiveness. Developers benefit from a declarative component syntax, reactivity baked directly into the language, and reduced boilerplate code compared to traditional JavaScript frameworks. The rich ecosystem of dev dependencies, including tools like Rollup, TypeScript, and ESLint, ensures a modern and well-supported development workflow. While this specific update focuses on a minor dev dependency change, upgrading often brings incremental improvements and optimizations, making it a worthwhile consideration for projects seeking cutting-edge performance and a smooth development experience.
All the vulnerabilities related to the version 3.17.2 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