Spring4Shell Vulnerability vs Log4Shell Vulnerability

On March 29, 2022, details of a zero-day vulnerability in Spring Framework (CVE-2022-22965) were leaked. For many, this is reminiscent of the zero-day vulnerability in Log4j (CVE-2021-44228) back in December 2021.   
What is the difference between the vulnerabilities?  
The Spring Framework vulnerability was caused by unforeseen access to Tomcat’s ClassLoader as a result of the new Module feature added in Java 9. The access could potentially allow an attacker to write a malicious JSP file accessible via the application server. …

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