GHSA-vh3f-qppr-j97f Mesh Connect JS SDK Vulnerable to Cross Site Scripting via createLink.openLink

• npm @meshconnect/web-link-sdk: < 3.3.2 → fixed in 3.3.2

Summary The lack of sanitization of URLs protocols in the `createLink.openLink` function enables the execution of arbitrary JavaScript code within the context of the parent page. Details https://github.com/FrontFin/mesh-web-sdk/blob/cf013b85ab95d64c63cbe46d6cb14695474924e7/packages/link/src/Link.ts#L441 The `createLink.openLink` function takes base64 encoded links, decodes them, and then sets the resulting string as the `src` attribute of an `iframe`. It’s important to note that the protocol part is not validated, so a payload, which is a valid URL, such as `javascript:alert(document.domain)//`, can be provided to the function. PoC 1. Extract poc-mesh-web-sdk.zip 2. Run `yarn install` and then `yarn start` 3. Paste this payload inside the input box: `amF2YXNjcmlwdDphbGVydCh3aW5kb3cucGFyZW50LmRvY3VtZW50LmJvZHkuZ2V0RWxlbWVudHNCeVRhZ05hbWUoImgyIikuaXRlbSgwKVsiaW5uZXJIVE1MIl0pLy8=` 4. Click on the _OpenLink_ button 5. Notice the alert box and ability to access the `h2` title from the parent page It can also be verified via `https://paylink.meshconnect.com/?linkToken=amF2YXNjcmlwdDphbGVydCgpLy8=`. Impact This is technically indistinguishable from a real page at the rendering level and allows access to the parent page DOM, storage, session, and cookies. If the attacker can specify `customIframeId`, they can hijack the source of existing iframes. If access to the private key is possible or if transactions are tampered with or initialized, in a wallet context, it can result in a critical impact due to loss of funds scenarios. Reporters • Amine `zwxxb` Elsassi of Aptos Labs