Svelte version 3.16.5 offers subtle enhancements over its predecessor, 3.16.4, continuing the evolution of this popular JavaScript framework for building performant web applications. Both versions maintain Svelte's core philosophy of shifting work from the browser to the compile step, resulting in smaller, faster, and more efficient web experiences. The developer experience remains consistent, leveraging familiar web technologies (HTML, CSS, and JavaScript) enhanced by Svelte's intuitive syntax.
While both versions share an identical set of development dependencies, crucial for testing, linting, and building Svelte components, a noteworthy difference resides in the unpacked size of the distribution. Version 3.16.5 weighs in at 3,034,845 bytes compared to 3,031,829 bytes for version 3.16.4. This potentially indicates minor bug fixes, performance tweaks, or internal adjustments. Developers should note the release dates. Version 3.16.5 was released on December 18, 2019, subsequent to the December 11, 2019 release of version 3.16.4. This timeframe suggests that 3.16.5 is likely a patch addressing issues identified in the earlier version. Keep your Svelte project up-to-date to benefit from the latest refinements and stability improvements in this cutting-edge framework, to ensure optimal performance and a smooth development workflow.
All the vulnerabilities related to the version 3.16.5 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