Unchecked buffer overrun in enc_untrusted_recvfrom

An arbitrary memory read vulnerability in Asylo versions up to 0.6.0 allows an untrusted attacker to make a call to enc_untrusted_recvfrom whose return size was not validated against the requested size. The parameter size is unchecked allowing the attacker to read memory locations outside of the intended buffer size including memory addresses within the secure enclave. We recommend upgrading past commit 6e158d558abd3c29a0208e30c97c9a8c5bd4230f