ModularSquareRoot in Crypto++ (aka cryptopp) through 8.9.0 allows attackers to cause a denial of service (infinite loop) via crafted DER public-key data associated with squared odd numbers, such as the square of 268995137513890432434389773128616504853.

gf2n.cpp in Crypto++ (aka cryptopp) through 8.9.0 allows attackers to cause a denial of service (application crash) via DER public-key data for an F(2^m) curve, if the degree of each term in the polynomial is not strictly decreasing.

Crypto++ (aka cryptopp) through 8.9.0 has a Marvin side channel during decryption with PKCS#1 v1.5 padding.

Crypto++ through 8.4 contains a timing side channel in ECDSA signature generation. Function FixedSizeAllocatorWithCleanup could write to memory outside of the allocation if the allocated memory was not 16-byte aligned. NOTE: this issue exists because the CVE-2019-14318 fix was intentionally removed for functionality reasons.

Crypto++ (aka Cryptopp) 8.6.0 and earlier contains a timing leakage in MakePublicKey(). There is a clear correlation between execution time and private key length, which may cause disclosure of the length information of the private key. This might allow attackers to conduct timing attacks. NOTE: this report is disputed by the vendor and multiple third parties. The execution-time differences are intentional. A user may make a choice of a longer key as a tradeoff between strength and performance. In making this choice, the amount of information leaked to an adversary is of infinitesimal value

The ElGamal implementation in Crypto++ through 8.5 allows plaintext recovery because, during interaction between two cryptographic libraries, a certain dangerous combination of the prime defined by the receiver's public key, the generator defined by the receiver's public key, and the sender's ephemeral exponents can lead to a cross-configuration attack against OpenPGP.

Crypto++ 8.3.0 and earlier contains a timing side channel in ECDSA signature generation. This allows a local or remote attacker, able to measure the duration of hundreds to thousands of signing operations, to compute the private key used. The issue occurs because scalar multiplication in ecp.cpp (prime field curves, small leakage) and algebra.cpp (binary field curves, large leakage) is not constant time and leaks the bit length of the scalar among other information.