Passing secrets (password) to a program via environmental variable is considered extremely insecure according to MySQL docs and as poor choice (from security aspect) across other resources.I would like to know why - what is it that I'm missing? In the mentioned MySQL manual(I'm using this as an example), passing password via -p option in command line is considered as insecure and via env var as extremely insecure, bold italic font.I'm not an expert but I do know the fundamentals: simple ps command, even issued by unprivileged user reads every program alongside with command parameters while only the same user (and root, of course) may read environment of the process. So, only root and johndoe may read environment of the johndoe - started process, while hacked www-data script reads all via ps.There must be some big deal here that I'm missing - so please explain me what am I missing?My objective is to have a mean of transferring secret from one program to other, generally, non-interactive.
Why is passing the secrets via environmental variables considered extremely insecure?
shell script;command line;security;environment variables;password
extremely insecure and should not be used. Some versions of ps include an option to display the environment of running processes. On some systems, if you set MYSQL_PWD, your password is exposed to any other user who runs ps.Elaborated on here (via):Background: in the process image argv[] and envp[] are stored in the same way, next to each other. In classic UNIXes /usr/bin/ps was typically setgid kmem (or similar group), which allowed it to dig around in /dev/kmem to read information about the active processes. This included the ability to read the process arguments AND the environment, of all users on the system.These days these privileged ps hacks are largely behind us: UNIX systems have all come up with different ways of querying such information (/proc on Linux, etc) I think all(?) of these consider a process's environment only to be readable by its uid. Thus, security-sensitive data like passwords in the environment aren't leaked.However, the old ways aren't 100% dead. Just as an example, here's an example from an AIX 5.2 machine I have access to, running as a non-root user[End-of-lifed: 2009.  Anyone know about more recent AIX?]...For the record, some while back we discovered (on IRC?) that OpenBSD 5.2 has this exact security exposure of leaking the environment to other local users (it was fixed shortly after that release, though).[Release year: 2012]