Svelte 1.5.0 represents a minor version increment over its predecessor, Svelte 1.4.0, both iterations maintaining Svelte's core promise as "the magical disappearing UI framework." Focusing on developer impact, the update, released on December 20, 2016, just two days after version 1.4.0, suggests a rapid iteration cycle addressing immediate improvements or bug fixes found in the prior release.
Examining the package data, notably, the dependencies and devDependencies remain identical between the two versions. Both rely on magic-string for string manipulation, essential for Svelte's compilation process. The extensive suite of devDependencies highlights the robust testing and development environment surrounding Svelte, including tools for code coverage (nyc, codecov), linting (eslint), bundling (rollup), and testing (mocha, jsdom). Babel plugins support modern JavaScript features, while Rollup plugins facilitate module resolution and commonjs compatibility.
The real significance of Svelte 1.5.0 to developers lies in the potential subtle enhancements and bug fixes it offered over 1.4.0. Without specific changelogs, users would have benefitted from a slightly more refined development experience, and a more stable application. In essence, upgrading from 1.4.0 to 1.5.0 would contribute to application's reliability and overall execution, solidifying Svelte as a reliable choice for building performant web applications. Svelte’s core philosophy of compiling away into highly optimized vanilla JavaScript at build time, and improves on the existing codebase for the best possible outcome.
All the vulnerabilities related to the version 1.5.0 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