Svelte 1.2.0 introduces a notable shift in dependency management compared to its predecessor, Svelte 1.1.3. While both versions share the core ambition of providing a "magical disappearing UI framework," the key difference lies in the dependencies section. Version 1.2.0 explicitly declares magic-string as a dependency, requiring version ^0.19.0. In contrast, Svelte 1.1.3 bundles magic-string as a devDependency.
This change suggests that magic-string, a library for manipulating strings with accurate source map generation, became a core requirement for Svelte's runtime operation in 1.2.0. This subtly could influence developers who relied on Svelte 1.1.3's implicit behavior where they might not need to install magic-string explicitly.
Both versions share a range of devDependencies essential for development, testing, and building, including tools like rollup, eslint, mocha, and various Babel plugins. The presence of rollup indicates the use of Svelte as a compiler, transforming Svelte components into highly optimized JavaScript during the build process. The eslint and other related plugins ensures code quality and consistency. These tools collectively create a good development environment and streamlined build process, promising a smoother experience when creating Svelte applications. The consistent license (MIT) and repository information underline the project's open-source commitment. The difference in release dates highlights the active development cycle, with both versions released within a very short time of each other, suggesting focused effort of improving the library.
All the vulnerabilities related to the version 1.2.0 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