Svelte version 3.7.1 arrives hot on the heels of 3.7.0, offering refinements and improvements to this innovative JavaScript framework known for its cybernetically enhanced web apps. Both versions maintain the core principle of compiling Svelte components into highly efficient vanilla JavaScript during the build process, resulting in faster load times and improved runtime performance compared to traditional virtual DOM approaches. Examining the metadata, the dependency lists between the two versions are identical pointing to internal improvements and bug fixes rather than feature additions. Key devDependencies remain consistent, from testing tools like Mocha and c8 for code coverage, to bundlers like Rollup and its associated plugins (@rollup/plugin-node-resolve, rollup-plugin-typescript) for optimized builds. Linting tools (eslint, @typescript-eslint/parser, eslint-plugin-svelte3) are identical, ensuring code quality and adherence to best practices. The key difference between the versions lies in the "dist" object, where the "unpackedSize" saw a slight increase from 2807476 to 2808407 bytes in version 3.7.1. as well as a difference of one day in the release date. This suggests minor code adjustments or additions, most likely bug fixes or performance tweaks, rather than significant new features. If you're already using Svelte 3.7.0, upgrading to 3.7.1 is recommended to benefit from these subtle enhancements and ensure a more stable and optimized development experience. It showcases the Svelte team's commitment to continuous improvement and refinement.
All the vulnerabilities related to the version 3.7.1 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