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![]() I can't think of any use in giving read or write permission to a directory without execute permission. Giving execute permission without giving read permission is occasionally useful: the names of entries serve as passwords to access them. ![]() Read permission on a directory gives the right to enumerate the entries. Also check your privileges over the processes binaries, maybe you can overwrite. setfacl -m user:joe:0 /* setfacl -d user:joe /bin /lib). To extract all the vulnerable kernel versions from that web you can do. For example, if / and /home are off-limits to joe ( setfacl -m user:joe:0 / /home) and /home/joe is joe's home directory, then joe won't be able to access the rest of the system (including running shell scripts with /bin/sh or dynamically linked binaries that need to access /lib, so you'd need to go deeper for practical use, e.g. This requires access control lists to be any use. Removing execute permission from the root directory effectively restricts a user to a part of the directory tree (which a more privileged process must change into). The permissions on the symlink itself may or may not matter depending on the OS and filesystem (some respect them, some ignore them). For example, if sym is a symbolic link to the directory dir, you need execute permission on dir to access sym/foo. The kernel uses the access rights of the calling process to traverse them. If a file has multiple hard links, the path you use to access it determines your access constraints. You can't change to /foo/bar in this scenario a more privileged process has presumably done cd /foo/bar before going unprivileged. For example, if you have execute permissions on /foo/bar but not on /foo, but your current directory is /foo/bar, you can access files in /foo/bar through a relative path but not through an absolute path. Posted: Octo Tyler Carrigan (Editorial Team, Red Hat) Image by Elyse Kiel of ERK Photography. Learn how to set the appropriate permissions, even in special circumstances. Getting into corner cases, I'm not sure whether it's universal that you need execute permission on the current directory to access a file through a relative path (you do on Linux). Getting permissions in Linux can sometimes be a 'sticky' situation. So for example to access dir/subdir/file, you need execute permission on dir and dir/subdir, plus the permissions on file for the type of access you want. ![]() ![]() The precise rule is: you can traverse a directory if and only if you have execute permission on it. ![]()
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