CVE-2021-38296: 
Java vulnerability analysis and mitigation

Apache Spark supports end-to-end encryption of RPC connections via "spark.authenticate" and "spark.network.crypto.enabled". In versions 3.1.2 and earlier, a vulnerability was discovered that allows for full encryption key recovery through a bespoke mutual authentication protocol. The vulnerability was assigned CVE-2021-38296 and was disclosed in March 2022. This issue affects Apache Spark installations using the mentioned authentication mechanisms, but does not impact security mechanisms controlled by "spark.authenticate.enableSaslEncryption", "spark.io.encryption.enabled", "spark.ssl", or "spark.ui.strictTransportSecurity" (NVD).

The vulnerability has a CVSS v3.1 Base Score of 7.5 (HIGH) with the vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N. This indicates that the vulnerability is network-accessible, requires low attack complexity, needs no privileges or user interaction, and primarily impacts confidentiality. The vulnerability is classified as CWE-294 (Authentication Bypass by Capture-replay) (NVD).

A successful exploitation of this vulnerability would allow an attacker to perform an initial interactive attack, after which they could decrypt plaintext traffic offline. This poses a significant risk to the confidentiality of data transmitted through affected Apache Spark RPC connections (NVD).

The recommended mitigation is to update to Apache Spark version 3.1.3 or later. Oracle has also released patches for affected products in their July 2022 Critical Patch Update (Oracle CPU).