37
votes
6answers
5k views

Unix execute permission can be easily bypassed. Is it superfluous, or what's the intention behind it?

The unix read permission is actually the same as the execute permission, so if e.g. one process has write access it's also able to execute the same file. This can be done pretty easily:First this ...
0
votes
2answers
296 views

Given an IP address can you ssh into /tmp without password?

I'm a Software Engineer, but I have no experience in security, so i'm trying to learn by doing (woot Experiential learning!). I know that the permission settings on the tmp folder are very relaxed. ...
0
votes
1answer
262 views

Would adding root to a group open a security hole?

I have a server for which I have created a cron job "sendalerts" to users. Mind you this "sendalerts.php" should be runnable from two methods (via browser and also via a cron job) So cron's job is to ...
3
votes
4answers
435 views

What mechanism enforces user permissions in Unix/Linux?

One of the core pieces of security in Unix/Linux systems is limiting privileges by user. For instance, certain actions can only be done by the root user. In theory, this can keep a malicious process ...
1
vote
2answers
225 views

What's the secure way to change UNIX permissions on a harcoded file often?

I'm writing a daemon that monitors something in the OS and flips execution permissions on a file in /run/ back and forth. The file has static contents and the file name is hardcoded in the daemon. I ...
2
votes
5answers
1k views

Security purpose of asking admin password to mount partition on Linux

So I divided my 250GB laptop drive into 2 partitions and some swap. On the second partition which is an ext4 60GB partition I installed Fedora 17. On the other bigger NTFS partition I've got Win XP ...
3
votes
1answer
374 views

Can UNIX Domain Sockets be locked by user ID?

If I created a folder /tmp/me with permissions 700, and started a process under me that starts a listen socket under /tmp/me/socket. I currently assume that a connection to that socket originated ...
6
votes
2answers
1k views

What are the dangers of storing webserver temp files in the /tmp/ folder?

I have configured my first publicly accessible nginx server. I have configured it to use a /tmp/nginx folder to store temp files. This includes the body of http requests, proxy files etc. The /tmp ...
8
votes
1answer
175 views

What is your default umask set to?

What is your default umask set to? Did you run into any problem setting a stricter default umask?