Jodit has prototype pollution via Jodit.configure() / ConfigMerge

Summary

Jodit.configure(options) — and the internal ConfigMerge / ConfigProto helpers — merged user-supplied options into the editor configuration without filtering prototype-mutating keys. A payload nested under an existing plain-object option such as controls could reach and mutate Object.prototype (prototype pollution).

Affected

• Package: jodit (npm)
• Versions: < 4.12.18
• Public API: Jodit.configure(options)

Proof of Concept

import { Jodit } from 'jodit';
delete Object.prototype.polluted;
Jodit.configure(JSON.parse('{"controls":{"__proto__":{"polluted":"yes"}}}'));
console.log(({}).polluted); // "yes" (before the fix)
delete Object.prototype.polluted;

Impact

Applications that pass user-controlled or partially user-controlled configuration into Jodit.configure() could be vulnerable to prototype pollution: unexpected property injection, logic bypass, denial of service, or secondary security issues.

Patch

Fixed in 4.12.18 by rejecting __proto__, constructor, and prototype at every merge level in ConfigMerge and ConfigProto.

Credit

Responsibly reported by Junming Wu.