curl: CURLSHOPT_UNSHARE race can cause UAF in shared SSL session cache during HTTPS transfer

Summary CURLSHOPTUNSHARE can free a shared SSL session cache while another thread is starting a normal HTTPS transfer with the same share handle. The failing transfer reaches the cache through curleasyperform, during the OpenSSL handshake. libcurl appears to try to reject this kind of lifetime...

DEBIAN-CVE-2014-3616

nginx 0.5.6 through 1.7.4, when using the same shared sslsessioncache or sslsessionticketkey for multiple servers, can reuse a cached SSL session for an unrelated context, which allows remote attackers with certain privileges to conduct "virtual host confusion" attacks...

UBUNTU-CVE-2014-3616

nginx 0.5.6 through 1.7.4, when using the same shared sslsessioncache or sslsessionticketkey for multiple servers, can reuse a cached SSL session for an unrelated context, which allows remote attackers with certain privileges to conduct "virtual host confusion" attacks...