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mbean's avatar
mbean
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Mar 31, 2022

spring4shell iRules yet?

Anyone have an irule to help alleviate this yet?

 

re: https://www.cyberkendra.com/2022/03/springshell-rce-0-day-vulnerability.html

 

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WAF protection

On network protection devices such as WAF, implement rule filtering for strings such as "class.*", "Class.*", "*.class.*", and "*.Class.*" according to the actual traffic situation of deployed services. After filtering the rules, test the business operation to avoid additional impact.
  • F5 has published additional Advanced WAF rules for CVE-2022-22965 (Spring4Shell) and CVE-2022-22963 (Spring Cloud RCE), in addition to the 0-day coverage provided by several existing rules: https://support.f5.com/csp/article/K24912123

    While you could likely use the log4j iRule as a base and modify it to contain your desired rules for Spring4Shell et al, I would caution that it is much more efficient and robust to use a WAF like Advanced WAF or NGINX App Protect than it is to re-write that functionality in an iRule.