Double free vulnerability in the ssl3_get_key_exchange function in the OpenSSL client (ssl/s3_clnt.c) in OpenSSL 1.0.0a, 0.9.8, 0.9.7, and possibly other versions, when using ECDH, allows context-dependent attackers to cause a denial of service (crash) and possibly execute arbitrary code via a crafted private key with an invalid prime.  NOTE: some sources refer to this as a use-after-free issue.