Package Instance

ASAR Integrity bypass via filetype confusion in electron
This only impacts apps that have the `embeddedAsarIntegrityValidation` and `onlyLoadAppFromAsar` [fuses](https://www.electronjs.org/docs/latest/tutorial/fuses) enabled.  Apps without these fuses enabled are not impacted.  This issue is specific to macOS as these fuses are only currently supported on macOS.

Specifically this issue can only be exploited if your app is launched from a filesystem the attacker has write access too.  i.e. the ability to edit files inside the `resources` folder in your app installation on Windows which these fuses are supposed to protect against.

Improper Check for Unusual or Exceptional Conditions
Electron is a framework which lets you write cross-platform desktop applications using JavaScript, HTML and CSS. Electron apps using `contextIsolation` and `contextBridge` are affected. This is a context isolation bypass, meaning that code running in the main world context in the renderer can reach into the isolated Electron context and perform privileged actions. This issue is only exploitable if an API exposed to the main world via `contextBridge` can return an object or array that contains a javascript object which cannot be serialized, for instance, a canvas rendering context. This would normally result in an exception being thrown `Error: object could not be cloned`. The app side workaround is to ensure that such a case is not possible. Ensure all values returned from a function exposed over the context bridge are supported. This issue has been fixed in versions `25.0.0-alpha.2`, `24.0.1`, `23.2.3`, and `22.3.6`.

Exfiltration of hashed SMB credentials on Windows via file:// redirect
### Impact
When following a redirect, Electron delays a check for redirecting to file:// URLs from other schemes. The contents of the file is not available to the renderer following the redirect, but if the redirect target is a SMB URL such as `file://some.website.com/`, then in some cases, Windows will connect to that server and attempt NTLM authentication, which can include sending hashed credentials.

### Patches
This issue has been fixed in all current stable versions of Electron. Specifically, these versions contain the fixes:

- 21.0.0-beta.1
- 20.0.1
- 19.0.11
- 18.3.7

We recommend all apps upgrade to the latest stable version of Electron.

### Workarounds
If upgrading isn't possible, this issue can be addressed without upgrading by preventing redirects to file:// URLs in the `WebContents.on('will-redirect')` event, for all WebContents:

```js
app.on('web-contents-created', (e, webContents) => {
  webContents.on('will-redirect', (e, url) => {
    if (/^file:/.test(url)) e.preventDefault()
  })
})
```

### For more information
If you have any questions or comments about this advisory, email us at [security@electronjs.org](mailto:security@electronjs.org).

### Credit
Thanks to user @coolcoolnoworries for reporting this issue.

Out-of-bounds Write
Heap buffer overflow in vp8 encoding in libvpx in Google Chrome prior to 117.0.5938.132 and libvpx 1.13.1 allowed a remote attacker to potentially exploit heap corruption via a crafted HTML page. (Chromium security severity: High)