Crypto++ (aka cryptopp and libcrypto++) 5.6.4 contained a bug in its ASN.1 BER decoding routine. The library will allocate a memory block based on the length field of the ASN.1 object. If there is not enough content octets in the ASN.1 object, then the function will fail and the memory block will be zeroed even if its unused. There is a noticeable delay during the wipe for a large allocation.

Crypto++ (aka cryptopp) through 5.6.4 does not document the requirement for a compile-time NDEBUG definition disabling the many assert calls that are unintended in production use, which might allow context-dependent attackers to obtain sensitive information by leveraging access to process memory after an assertion failure, as demonstrated by reading a core dump.

The InvertibleRWFunction::CalculateInverse function in rw.cpp in libcrypt++ 5.6.2 does not properly blind private key operations for the Rabin-Williams digital signature algorithm, which allows remote attackers to obtain private keys via a timing attack.