Improper Input Validation

1. In the latest 2.0.2 there was a rewrite of the IP validation. Effectively, in version 2.0.2 the sanity check that IP components are < 0xFFFFFFFF has been removed, because >>> 0 always converts them to a 32-bit unsigned long.
   This can cause trouble, for example this "IP" actually checks out as belonging to the localhost block: "4294967423.0.0.1" (because mod 2^32 it is equal to 127.0.0.1).
   Although it's obviously an invalid IP, this has the potential to create shenanigans, because other libraries probably are not making the exact same mistake.

2. Another input validation issue is the use of the ParseInt function for the mask parameter. For example two possible inputs that generate a nonsensical state:
   (a) Try weird = new Netmask('1.2.3.4', -1) , and then the state of the netmask object includes a bitmask <0, and size > 2^32 among other oddities. The next() operation has an uncaught error in this case.
   (b) Try weird2 = new Netmask('1.2.3.4', 0.1). The constructor succeeds, but the state is similarly funky.

Best regards,
Alon Navon,
Seal Security

Start at the Netmask constructor and the next() operation described in the report, then trace the IP component and mask parsing paths. Use the reported oversized, negative, and fractional inputs as regression cases; done means these inputs are rejected or otherwise cannot leave the object in the invalid states described.