A sneaky demonstration of the dangers of curl | bash - k3can blog
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I set up a quick demonstration to show risks of curl|bash and how a bad-actor could potentially hide a malicious script that appears safe.

It’s nothing new or groundbreaking, but I figure it never hurts to have another reminder.

  • Flipper@feddit.orgEnglish
    12·
    29 minutes ago

    Its timing based. When piped a script, bash executes each line completly before taking the next line from the input. Curl has a limited output buffer.

    1. Operation that takes a long time. Like a sleep, or if you want it less obvious. A download, an unzip operation, apt update, etc.
    2. Fill the buffer with more bash commands.
    3. Measure on the server if at some point curl stops downloading the script.
    4. Serve a malicious payload.