Caucho Quercus, as distributed in Resin before 4.0.29, does not properly implement the == (equals sign equals sign) operator for comparisons, which has unspecified impact and context-dependent attack vectors.
Caucho Quercus, as distributed in Resin before 4.0.29, allows remote attackers to bypass intended restrictions on filename extensions for created files via a %00 sequence in a pathname within an HTTP request.