Svelte 2.7.1 is a minor patch release following version 2.7.0 in the Svelte UI framework, known for its "magical disappearing" act by compiling components into highly efficient vanilla JavaScript during build time. Both versions share identical development dependencies, incorporating tools for testing (mocha, nyc, jsdom), linting (eslint, eslint-plugin-html, eslint-plugin-import), bundling (rollup) and tooling (ts-node, typescript), indicating a consistent development environment. Developers utilising Svelte benefit of an extensive ecosystem for creating performant web applications.
The key difference between the two lies in the dist metadata, where 2.7.1 shows a minor increase in unpackedSize (2568454 bytes versus 2568291 bytes in 2.7.0) and a later releaseDate demonstrating incremental improvements or bug fixes. While both versions offer the same core functionality, choosing 2.7.1 over 2.7.0 ensures you are receiving the latest enhancements and the fixes from the prior version. For developers, this translates to a more stable platform and potentially improved performance in their Svelte applications. It's a strategic decision that aligns well with best practices in modern web development, emphasizing consistency and maintaining the newest available features.
All the vulnerabilities related to the version 2.7.1 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