Medium · published February 9, 2023
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.
| Product | Versions | Fixed in |
|---|---|---|
| openssl/openssl | ≥ 1.0.2, < 1.0.2zg | 1.0.2zg |
| openssl/openssl | ≥ 1.1.1, < 1.1.1t | 1.1.1t |
| openssl/openssl | ≥ 3.0.0, < 3.0.8 | 3.0.8 |
| stormshield/endpoint_security | < 7.2.40 | 7.2.40 |
| stormshield/sslvpn | < 3.2.1 | 3.2.1 |
| stormshield/stormshield_network_security | ≥ 2.7.0, < 2.7.11 | 2.7.11 |
| stormshield/stormshield_network_security | ≥ 2.8.0, < 3.7.34 | 3.7.34 |
| stormshield/stormshield_network_security | ≥ 3.8.0, < 3.11.22 | 3.11.22 |
| stormshield/stormshield_network_security | ≥ 4.0.0, < 4.3.16 | 4.3.16 |
| stormshield/stormshield_network_security | ≥ 4.4.0, < 4.6.3 | 4.6.3 |