Svelte 1.29.2 and 1.29.1 are minor version updates of the Svelte UI framework, a tool known for its "disappearing" nature, compiling components into highly efficient vanilla JavaScript during the build process. Both versions share identical development dependencies, including tools for testing (mocha, jsdom, nyc, codecov), linting (eslint, prettier, eslint-plugin-html, eslint-plugin-import), module bundling (rollup, rollup-plugin-*, rollup-watch), TypeScript support (typescript, @types/node, @types/mocha, rollup-plugin-typescript), and utilities for source map handling (source-map, source-map-support), string manipulation (magic-string), and AST traversal (estree-walker).
Essentially, the core development environment and toolchain remain consistent between these two versions. The key difference lies in the release date: version 1.29.2 was published on August 13, 2017, whereas version 1.29.1 was released on August 9, 2017. This indicates that 1.29.2 is a patch release addressing potentially minor bug fixes or improvements identified after the initial 1.29.1 release.
While the specific changes between these versions aren't detailed here, developers should consider upgrading to 1.29.2 to benefit from any bug fixes or small enhancements, ensuring a smoother and more reliable development experience when building performant web applications with Svelte. Always consult the official Svelte changelog or release notes for detailed information on what was changed.
All the vulnerabilities related to the version 1.29.2 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