nmap: Which version did OS scan and MAC address start needing root permissions?

Question

I would like to run the OS identification abilities of nmap and be able to get the MAC address of a device with out sudo privilege. In which versions did this change?

Answer 1

As far as I know, it has always been necessary to have root permissions for the OS fingerprinting and MAC address features. The earliest mention in the CHANGELOG for this requirement is for Nmap 4.23RC2 [2007-11-18]:

o Reworded an error message after a woman reported that it was "highly
  offensive and sexist".  She also noted that "times have changed and
  many women now use your software" and "a sexist remark like the one
  above should have no place in software."  The message was: "TCP/IP
  fingerprinting (for OS scan) requires root privileges. Sorry,
  dude.".  I checked svn blame to call out the insensitive,
  chauvinistic jerk who wrote that error message, but it was me :).

As a workaround for the MAC address part (which is a side-effect of sniffing packets directly from the network to gather responses, which requires root), you can use the arp -an command to list the entries in your system's ARP table which are populated by the OS from Nmap's activity. Nmap itself does not check this because methods for checking the ARP cache are not portable.