broken.xml:  
<?xml version="1.0" encoding="UTF-8"?>  
<!DOCTYPE data SYSTEM "data.dtd">  
<data>  
  <user>admin & test</user>  
</data>  
  
testcase.cpp:  
#include <libxml++/libxml++.h>  
  
int main(void)  
{  
    while (1) {  
        try {  
            xmlpp::DomParser parser;  
            parser.set_validate(false);  
            parser.parse_file("broken.xml");  
        } catch(...) {  
        }  
    }  
  
    return 0;  
}