Vulnerability in OpenSSL - ASN.1 BIO excessive memory allocation

When ASN.1 data is read from a BIO using functions such as d2i_CMS_bio() a short invalid encoding can casuse allocation of large amounts of memory potentially consuming excessive resources or exhausting memory. Any application parsing untrusted data through d2i BIO functions is affected. The memory based functions such as d2i_X509() are not affected. Since the memory based functions are used by the TLS library, TLS applications are not affected.

Found by Brian Carpenter.