Svelte version 2.3.0 represents a minor update over version 2.2.0 in the Svelte UI framework, known for its "magical disappearing" act where the compiler transforms code into highly efficient vanilla JavaScript during build time. Both versions share the same core philosophy and maintain identical development dependencies, including tools for linting (eslint), bundling (rollup), testing (mocha, jsdom, nightmare), and TypeScript support. The core dependencies are almost identical. Developers familiar with 2.2.0 would find a seamless transition to 2.3.0.
The key difference lies in subtle improvements and potential bug fixes incorporated between the two releases. The release date of version 2.3.0 is slightly later (April 29, 2018) than version 2.2.0 (April 29, 2018 i.e. the day before), indicating a quick follow-up release. While specific details regarding the improvements are not available in this data, one notable change is the subtle increase in unpacked size (2,514,381 bytes vs 2,517,719 bytes) which may be because of minor updates to the core. Developers should refer to the official Svelte changelog or release notes for a comprehensive list of changes but from this data the differences are very smalls.
All the vulnerabilities related to the version 2.3.0 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