OpenSSL -- CMS and S/MIME Bleichenbacher attack

ID 60EB344E-6EB1-11E1-8AD7-00E0815B8DA8
Type freebsd
Reporter FreeBSD
Modified 2012-03-12T00:00:00


The OpenSSL Team reports:

A weakness in the OpenSSL CMS and PKCS #7 code can be exploited using Bleichenbacher's attack on PKCS #1 v1.5 RSA padding also known as the million message attack (MMA). Only users of CMS, PKCS #7, or S/MIME decryption operations are affected. A successful attack needs on average 2^20 messages. In practice only automated systems will be affected as humans will not be willing to process this many messages. SSL/TLS applications are NOT affected by this problem since the SSL/TLS code does not use the PKCS#7 or CMS decryption code.