OSV-2020-1315 Heap-buffer-overflow in pcpp::IPv4Layer::getFragmentFlags

OSS-Fuzz report: https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=22638 Crash type: Heap-buffer-overflow READ 2 Crash state: pcpp::IPv4Layer::getFragmentFlags pcpp::IPv4Layer::isFragment pcpp::IPv4Layer::parseNextLayer...