CVE-2022-4304 – Timing Oracle in RSA Decryption

https://notcve.org/view.php?id=CVE-2022-4304

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. • https://security.gentoo.org/glsa/202402-08 https://www.openssl.org/news/secadv/20230207.txt https://access.redhat.com/security/cve/CVE-2022-4304 https://bugzilla.redhat.com/show_bug.cgi?id=2164487 • CWE-203: Observable Discrepancy •