Ubuntu Security Notice 4990-1 - It was discovered that Nettle incorrectly handled RSA decryption. A remote attacker could possibly use this issue to cause Nettle to crash, resulting in a denial of service. It was discovered that Nettle incorrectly handled certain padding oracles. A remote attacker could possibly use this issue to perform a variant of the Bleichenbacher attack. This issue only affected Ubuntu 18.04 LTS. Various other issues were also addressed.
18ac1040641e10f745441e19c4e76450403a73af58de924392fb2255e3dfadc1