CVE-2024-45047: Potential mXSS vulnerability due to improper HTML escaping in svelte

Vulnerability summary

CVE-2024-45047 is a medium (CVSS 6.1) vulnerability in svelte. EPSS estimates a 0.36% chance of exploitation in the next 30 days, higher than 30.3% of scored vulnerabilities. 1 public exploit is recorded.

Timeline

1. 30-08-2024
   PublishedVulnerability first disclosed.
2. 30-08-2024
   Last modifiedVulnerability information updated.

Description

svelte performance oriented web framework. A potential mXSS vulnerability exists in Svelte for versions up to but not including 4.2.19. Svelte improperly escapes HTML on server-side rendering. 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, and a type of the XSS is known as mXSS (mutation XSS). More specifically, this can occur when injecting malicious content into an attribute within a `noscript` tag. This issue has been addressed in release version 4.2.19. Users are advised to upgrade. There are no known workarounds for this vulnerability.

• CWE-79Improper Neutralization of Input During Web Page GenerationThe product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users.