Spree 0.2.0 does not properly restrict the use of a hash to provide values for a model's attributes, which allows remote attackers to set the Order state value and bypass the intended payment step via a modified URL, related to a "mass assignment" vulnerability.
Exploitability
AV:NAC:LAu:NImpact
C:NI:PA:N5/AV:N/AC:L/Au:N/C:N/I:P/A:N