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The following line of vulnerable code makes the user input always upper case:

mysql_query("select * from " . strtoupper($_GET['table']));

In a scenario where MySQL's "lower_case_table_names" is set to 0 (case sensitive schema and table comparisons), I'm unable to read data from lowecase tables. Is there any way to bypass this?

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  • You can extract the actual name from the Schema information, (show tables) and use that in a union select.
    – Tobi Nary
    Sep 16, 2017 at 18:08
  • @SmokeDispenser I've tried a lot of similar stuff without luck. How would I concatenate the name from information_schema to FROM? Can you please provide a working example? Sep 16, 2017 at 18:11
  • Not off the top of my head, but along these lines: dev.mysql.com/doc/refman/5.7/en/derived-tables.html
    – Tobi Nary
    Sep 16, 2017 at 18:27
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    @SmokeDispenser I know where you are coming from, but I don't think it'll work. Whether we use union or sub-selects, at some point it's necessary to specify table name and since we cannot use any variables without a prepared statement, I don't see a way to bypass the upper case. I was thinking about collations (dev.mysql.com/doc/refman/5.7/en/charset-collate.html) or some modifiers that can force a case insensitive select Sep 16, 2017 at 20:32
  • Duplicate of security.stackexchange.com/questions/169858/…
    – Nate
    Sep 21, 2017 at 18:28

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