Svelte version 3.34.0 is a minor release following 3.33.0, both iterations of the "cybernetically enhanced web apps" framework, boasting minimal differences in their core devDependencies. Both releases share the same suite of development tools, including testing frameworks like Mocha and C8 for code coverage, linting via ESLint, and bundling powered by Rollup. Key utilities like magic-string for source code manipulation and css-tree for CSS parsing remain consistent, ensuring a stable development environment. The consistent usage of @rollup/plugin-* for various transformations, such as JSON handling, replacing variables, and using Sucrase/Typescript, highlight Svelte's dedication to modern JavaScript development practices.
The critical distinction lies in the dist metadata. Version 3.34.0 features a slightly larger unpacked size of 6558219 bytes compared to 3.33.0's 6555081 bytes. Although the file count remains the same at 217, this indicates minor internal adjustments, potentially bug fixes or performance improvements that don't drastically alter the API surface. Developers upgrading from 3.33.0 can expect a seamless transition, benefiting from under-the-hood optimizations without encountering breaking changes. The updated release date suggests the newer version includes the latest fixes. Both releases remain under the MIT license, ensuring open-source flexibility and community collaboration. This makes Svelte a competitive option.
All the vulnerabilities related to the version 3.34.0 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