A flaw was found in the way nettle's RSA decryption functions handled specially crafted ciphertext. An attacker could use this flaw to provide a manipulated ciphertext leading to application crash and denial of service.

A flaw was found in Nettle in versions before 3.7.2, where several Nettle signature verification functions (GOST DSA, EDDSA & ECDSA) result in the Elliptic Curve Cryptography point (ECC) multiply function being called with out-of-range scalers, possibly resulting in incorrect results. This flaw allows an attacker to force an invalid signature, causing an assertion failure or possible validation. The highest threat to this vulnerability is to confidentiality, integrity, as well as system availability.

A Bleichenbacher type side-channel based padding oracle attack was found in the way nettle handles endian conversion of RSA decrypted PKCS#1 v1.5 data. An attacker who is able to run a process on the same physical core as the victim process, could use this flaw extract plaintext or in some cases downgrade any TLS connections to a vulnerable server.

The RSA and DSA decryption code in Nettle makes it easier for attackers to discover private keys via a cache side channel attack.

The ecc_256_modq function in ecc-256.c in Nettle before 3.2 does not properly handle carry propagation and produces incorrect output in its implementation of the P-256 NIST elliptic curve, which allows attackers to have unspecified impact via unknown vectors, a different vulnerability than CVE-2015-8803.

x86_64/ecc-384-modp.asm in Nettle before 3.2 does not properly handle carry propagation and produces incorrect output in its implementation of the P-384 NIST elliptic curve, which allows attackers to have unspecified impact via unknown vectors.

The ecc_256_modp function in ecc-256.c in Nettle before 3.2 does not properly handle carry propagation and produces incorrect output in its implementation of the P-256 NIST elliptic curve, which allows attackers to have unspecified impact via unknown vectors, a different vulnerability than CVE-2015-8805.