Svelte version 1.34.0 arrived on August 29, 2017, a single day after version 1.33.0. Both versions showcase Svelte's core proposition as "the magical disappearing UI framework," emphasizing its compile-time approach that translates components into highly efficient vanilla JavaScript. Examining the devDependencies reveals a consistent toolchain focused on building, testing, and linting the Svelte compiler. Developers using Svelte in this era benefited from a robust ecosystem of tools like Rollup for bundling, ESLint for code quality, and TypeScript for optional static typing.
A close comparison of the two versions doesn't show any changes regarding dependencies or core metadata. This usually suggests potentially internal bug fixes, performance improvements or documentation updates that were deemed important enough to warrant a patch release. For developers, this means that transitioning from 1.33.0 to 1.34.0 should be seamless. Considering the extremely close release dates, upgrading is advisable. It's a prime example of Svelte's commitment to stability and continuous improvement, ensuring a reliable foundation for building reactive web applications. Developers seeking a lightweight and performant UI framework could confidently rely on these Svelte versions, taking advantage of the compiler's optimization capabilities and the supportive development environment. Svelte's approach allowed for building web apps delivering excellent performance and a great development experience.
All the vulnerabilities related to the version 1.34.0 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