Sandboxed Mac apps can take screenshots of the full screen

Originator:KrauseFx
Number:rdar://37423927 Date Originated:February 10 2018
Status:Open Resolved:
Product: Product Version:
Classification: Reproducible:Always
 
Area:
App Sandbox

Summary:

Any Mac app, sandboxed or not sandboxed can:

- Take screenshots of your Mac silently without you knowning
- Access every pixel, even if the Mac app is in the background
- Use basic OCR software to read the text on the screen

Steps to Reproduce:

1. Create a new Mac project
1. 
```objective-c
CGImageRef screenShot = CGWindowListCreateImage(CGRectInfinite, kCGWindowListOptionOnScreenOnly, kCGNullWindowID, kCGWindowImageDefault);

NSBitmapImageRep *bitmapRep = [[NSBitmapImageRep alloc] initWithCGImage:screenShot];
```
1. See the full screen of the user in the `bitmapRep` variable

Expected Results:
This shouldn't be possible for sandboxed Mac applications, without extra permission.

Actual Results:
Any Mac app can read the content of the whole screen, making it easy to parse the text using basic OCR software.

Version/Build:
Xcode 9.1

Configuration:

Comments


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