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Starred by 2 users
Status: Fixed
Owner:
Email to this user bounced
Closed: Aug 2015
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Adobe Flash: Type Confusion in TextRenderer.setAdvancedAntialiasingTable
Project Member Reported by natashenka@google.com, May 27 2015 Back to list
There is a type confusion issue in TextRenderer.setAdvancedAntialiasingTable. If the font, insideCutoff or outsideCutoff are set to objects that are not integers, they are still assumed to be integers. A proof-of-concept is below:

var antiAliasEntry_1 = {fontSize:10, insideCutoff:1.61, outsideCutoff:-3.43};
var antiAliasEntry_2 = {fontSize:"", insideCutoff:0.8, outsideCutoff:-0.8};
var arialTable:Array = new Array(antiAliasEntry_1, antiAliasEntry_2);

TextRenderer.setAdvancedAntialiasingTable("Arial", "none", "dark", arialTable);

This issue is low-impact because the type-confused objects are read into the font and cutoff values, which cannot be directly retreived from script. It is probably possible to determine the value read by doing hit tests on the text that is rendered (to see how big and clipped it is), but this would be fairly difficult.

A sample SWF and fla are attached, these samples intentionally crash to demonstrate the issue. 

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.
 
antialias2.swf
153 KB Download
antialias2.fla
5.3 KB Download
Project Member Comment 1 by scvitti@google.com, May 28 2015
Labels: -Reported-2015-05-27 Reported-2015-May-27
Project Member Comment 2 by natashenka@google.com, May 29 2015
Labels: -Reported-2015-May-27 Reported-2015-May-29
Project Member Comment 3 by natashenka@google.com, Jun 1 2015
This is PSIRT-3767
Project Member Comment 4 by natashenka@google.com, Aug 11 2015
Labels: Id-3767 CVE-2015-5555
Status: Fixed
Project Member Comment 6 by natashenka@google.com, Aug 18 2015
Labels: -Restrict-View-Commit
Fixed in https://helpx.adobe.com/security/products/flash-player/apsb15-19.html
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