CVE-2022-4304
Timing Oracle in RSA Decryption
Description
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.
How to fix CVE-2022-4304
To remediate CVE-2022-4304, upgrade the affected package to a fixed version below.
- —upgrade to 1.1.1t-r0 or later
- —upgrade to 3.0.8-r0 or later
- —upgrade to 111.25.0 or later
- —upgrade to 111.25.0 or later
- —upgrade to 1.1.1n-0+deb11u4 or later
Is CVE-2022-4304 being exploited?
Low — EPSS is 0.2%, meaning exploitation activity has not been observed at scale.
Affected packages (5)
- from 0, < 1.1.1t-r0
- from 0, < 3.0.8-r0
- from 0, < 111.25.0
- >= 0.0.0-0, < 111.25.0, >= 300.0.0, < 300.0.12
- from 0, < 1.1.1n-0+deb11u4
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 3.1 | MEDIUM5.9 | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N |