Headline
GHSA-p2jh-44qj-pf2v: 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:
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 [email protected].
Credit
Thanks to user @coolcoolnoworries for reporting this issue.
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:
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 [email protected].
Credit
Thanks to user @coolcoolnoworries for reporting this issue.
References
- GHSA-p2jh-44qj-pf2v
- https://nvd.nist.gov/vuln/detail/CVE-2022-36077
Related news
The Electron framework enables writing cross-platform desktop applications using JavaScript, HTML and CSS. In versions prior to 21.0.0-beta.1, 20.0.1, 19.0.11, and 18.3.7, Electron is vulnerable to Exposure of Sensitive Information. 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 patched in versions: 21.0.0-beta.1, 20.0.1, 19.0.11, and 18.3.7. Users are recommended to 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 as a workaround.