karo Metacharacter Handling Remote Command Execution

The karo gem through 2.5.2 for Ruby allows Remote command injection via the host field.

A flaw in db.rb is triggered when handling metacharacters. This may allow a remote attacker to execute arbitrary commands.

In particular lines 76 and 95 (as of 2014-06-01) pass unsanitized user supplied input to the command line.

73-      host = "{@configuration["user"]}@{@configuration["host"]}"
74-      cmd  = "ssh #{host} cat {server_db_config_file}"
75-
76:      server_db_config_output = `{cmd}`
79-
--
89- def drop_and_create_local_database(local_db_config)
90-      command = case local_db_config["adapter"]
91-      when "mysql2"
93-      when "postgresql"
95-          dropdb -h #{local_db_config["host"]} -U #{local_db_config["username"]} --if-exists #{local_db_config["database"]}

If this gem is used in the context of a rails application malicious input could lead to remote command injection. As of version 2.5.2 the affected code lines have not changed.