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On November 1, 2022, OpenSSL disclosed [1] OpenSSL vulnerabilities including CVE-2022-4304 involving 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. This vulnerability affects the ACOS SSL/TLS Data Plane and Management Plane and is addressed in this document.
| Item # |
Vulnerability ID |
Score Source |
Score |
Summary |
| 1 | CVE-2022-4304 | CVSSv3 | 5.9 Medium | openssl: timing attack in RSA Decryption implementation [2] |
The table below indicates releases of ACOS exposed to this vulnerability and ACOS releases that address them. ACOS release families not indicated below are unaffected by these vulnerabilities.
Customers using affected ACOS releases can overcome vulnerability exposures by updating to the indicated resolved release. If the table does not list a corresponding resolved or unaffected release, then no ACOS release update is currently available.
| Releases Affected | Releases Resolved or Unaffected |
|---|---|
| 5.0.0 – 5.2.1-P6 | 5.2.1-P7 for Data Plane |
| 5.0.0 – 5.2.1 | None (a) for Management Plane |
| 4.1.4-GR1 | 5.2.1-P7 for Data Plane |
| 4.1.4-GR1 | None (a) for Management Plane |
(a) A10 continues to plan remediation for 5.2.1 and 4.1.4-GR1 Management Plane, pending availability of integrated corrections from upstream operating system providers.
This issue is valid for the 4.1.4 Data Plane Software SSL. 4.1.4 Hardware SSL is not affected.
To mitigate this issue, A10 recommends upgrading to 5.2.1-P7 and use swssl-tls13 mode.
Software updates that address these vulnerabilities are or will be published at the following URL:
The following table shares brief descriptions for the vulnerabilities addressed in this document.
| Vulnerability ID | Vulnerability Description |
|---|---|
| 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. |
| Ref # | General Link |
|---|---|
| 1 | https://www.openssl.org/news/secadv/20230207.txt |
| 2 | http://nvd.nist.gov/vuln/detail/CVE-2022-4304 |
None
| Revision | Date | Description |
|---|---|---|
| 1.0 | April 28, 2023 |
Initial Publication |
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