CVE-2022-4304: OpenSSL

Medium severity, CVSS 5.9. EPSS: 16.2% chance of exploitation in the next 30 days.

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.

Affected products

• OpenSSL OpenSSL: from 1.0.2, before 1.0.2zg (fixed in 1.0.2zg); from 1.1.1, before 1.1.1t (fixed in 1.1.1t); from 3.0.0, before 3.0.8 (fixed in 3.0.8)
• Stormshield Endpoint Security: before 7.2.40 (fixed in 7.2.40)
• Stormshield SSLVPN: before 3.2.1 (fixed in 3.2.1)
• Stormshield Stormshield Network Security: from 2.7.0, before 2.7.11 (fixed in 2.7.11); from 2.8.0, before 3.7.34 (fixed in 3.7.34); from 3.8.0, before 3.11.22 (fixed in 3.11.22); from 4.0.0, before 4.3.16 (fixed in 4.3.16); from 4.4.0, before 4.6.3 (fixed in 4.6.3)

Published 2023-02-08. Last modified 2026-06-17.