not checking return value of sandbox mkdir is a security issue

tsgates / mbox

A lightweight sandbox tool for non-root users

http://pdos.csail.mit.edu/mbox/

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not checking return value of sandbox mkdir is a security issue #2

Open Habbie opened 10 years ago

Habbie commented 10 years ago

The default sandbox dir is /tmp/sandbox-%d (with getpid). This is very predictable. Then, the return value of mkdir(opt_root, 0755); is not checked. This means a different system user could pre-create the sandbox dir and inject files into it.

Checking the return value of mkdir (and aborting on EEXIST) would fix this. I'm also not sure 0755 is the best default.

tsgates commented 10 years ago

thanks. fixed.