Multiline mode in regexp by default
When using regexp there can be a vulnerability:
Probably it happens because multiline mode in regexp is default, but this is wrong. Need use 'm' modificator to use this mode.
#1 [ruby-core:45149] Updated by Xavier Noria about 4 years ago
In Ruby there is no multiline flag, regexps in Ruby are always in multiline mode. See http://advogato.org/person/fxn/diary/498.html for some gotchas regarding regexp flags in Perl vs Ruby.
In Ruby, you need to use \A and \z (or \Z) to match start and end of string.