curl -u username:password http://example.com secure?
If not, can you give a brief explanation of how someone could obtain your password?
It is unsafe, because cURL defaults to basic authentication where HTTP protocol sends your password in clear text. When you specify the
username:password string, it gets converted to a BASE64 string in the HTTP header:
GET / HTTP/1.1 Host: example.com User-Agent: Mozilla/5.0 Accept: text/html Authorization: Basic dXNlcm5hbWU6cGFzc3dvcmQ=
Anyone able to intercept your HTTP traffic (your provider, anyone accessing the same wireless AP as you etc) will be able to recover the password by simply using an online BASE64 converter.
HTTPS protocol will make things better by establishing an encrypted connection before this header is sent, preventing the password from being revealed. However, this only applies if the user pays attention when asked to confirm unknown certificates, authorize security exceptions and so on.
Note that command arguments might be available for other users on the same machine to see, e.g.
ps -ef, /proc filesystem, in you bash history, and in your terminal log (thanks for @Lambert's comment noting this). cURL on some platforms attempts to hide the password so for example with
ps -ef you are likely to see blank space instead of a password. However, instead of passing the password as a command line argument, having cURL directly prompt for a password is better, as discussed on the cURL faq.
This could be done in a more safer way by using --netrc-file parameter.
For eg: vi /root/my-file
Save and Close the file
curl --netrc-file /root/my-file http://example.com
Short answer is no... but....
If there are no server side options you can harden the security.
None of these are any less secure than a browser using HTTP.