CVE-2023-22946: Apache Spark proxy-user privilege escalation from malicious configuration class

["Sean R. Owen" <srowen () apache org>]

Description:

In Apache Spark versions prior to 3.4.0, applications using spark-submit can specify a 'proxy-user' to run as, limiting 
privileges. The application can execute code with the privileges of the submitting user, however, by providing 
malicious configuration-related classes on the classpath. This affects architectures relying on proxy-user, for example 
those using Apache Livy to manage submitted applications.

This issue is being tracked as SPARK-41958 

Work Arounds:

Update to Apache Spark 3.4.0 or later, and ensure that spark.submit.proxyUser.allowCustomClasspathInClusterMode is set 
to its default of "false", and is not overridden by submitted applications.

Credit:

Hideyuki Furue (finder)
Yi Wu (Databricks) (remediation developer)

References:

https://spark.apache.org/
https://www.cve.org/CVERecord?id=CVE-2023-22946
https://issues.apache.org/jira/browse/SPARK-41958