CVE-2015-2928 "disgleirio" discovered that a malicious client could trigger an assertion failure in a Tor instance providing a hidden service, thus rendering the service inaccessible. CVE-2015-2929 "DonnchaC" discovered that Tor clients would crash with an assertion failure upon parsing specially crafted hidden service descriptors. Introduction points would accept multiple INTRODUCE1 cells on one circuit, making it inexpensive for an attacker to overload a hidden service with introductions. Introduction points now no longer allow multiple cells of that type on the same circuit.