CVSS3
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
CHANGED
Confidentiality Impact
LOW
Integrity Impact
NONE
Availability Impact
LOW
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:N/A:L
EPSS
Percentile
31.3%
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.
This issue has been fixed in all current stable versions of Electron. Specifically, these versions contain the fixes:
We recommend all apps upgrade to the latest stable version of Electron.
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:
app.on('web-contents-created', (e, webContents) => {
webContents.on('will-redirect', (e, url) => {
if (/^file:/.test(url)) e.preventDefault()
})
})
If you have any questions or comments about this advisory, email us at [email protected].
Thanks to user @coolcoolnoworries for reporting this issue.