A timing based side channel exists in the OpenSSL RSA Decryption implementation which could be sufficient to recover a plaintext across a network in a Bleichenbacher style attack. To achieve a successful decryption an attacker would have to be able to send a very large number of trial messages for decryption. The vulnerability affects all RSA padding modes: PKCS#1 v1.5, RSA-OEAP and RSASVE.

For example, in a TLS connection, RSA is commonly used by a client to send an encrypted pre-master secret to the server. An attacker that had observed a genuine connection between a client and a server could use this flaw to send trial messages to the server and record the time taken to process them. After a sufficiently large number of messages the attacker could recover the pre-master secret used for the original connection and thus be able to decrypt the application data sent over that connection.

A use-after-free vulnerability was found in OpenSSL's BIOnewNDEF function. The public API function BIOnewNDEF is a helper function used for streaming ASN.1 data via a BIO. It is primarily used internally by OpenSSL to support the SMIME, CMS, and PKCS7 streaming capabilities, but it may also be called directly by end-user applications. The function receives a BIO from the caller, prepends a new BIOfasn1 filter BIO onto the front of it to form a BIO chain, and then returns the new head of the BIO chain to the caller. Under certain conditions. For example, if a CMS recipient public key is invalid, the new filter BIO is freed, and the function returns a NULL result indicating a failure. However, in this case, the BIO chain is not properly cleaned up, and the BIO passed by the caller still retains internal pointers to the previously freed filter BIO. If the caller then calls BIOpop() on the BIO, a use-after-free will occur, possibly resulting in a crash.