Amazon Linux AMI: CVE-2022-4304: Security patch for openssl (ALAS-2023-1683)

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.