1.2 KiB
[advisory]
id = "RUSTSEC-2023-0007"
package = "openssl-src"
aliases = ["CVE-2022-4304", "GHSA-p52g-cm5j-mjv4"]
categories = ["crypto-failure"]
date = "2023-02-07"
url = "https://www.openssl.org/news/secadv/20230207.txt"
[versions]
patched = [">= 111.25, < 300.0", ">= 300.0.12"]
Timing Oracle in RSA Decryption
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.