Merge pull request #388 from cisagov/add-ed-guidance

Add CISA rec mitigation guidance

README.md

@@ -20,7 +20,8 @@ or imply their endorsement, recommendation, or favoring by CISA.
 ## Official CISA Guidance & Resources ##
 
 - [CISA Apache Log4j Vulnerability Guidance](https://www.cisa.gov/uscert/apache-log4j-vulnerability-guidance)
-- [ALERT (AA21-356A): Mitigating Log4Shell and Other Log4j-Related Vulnerabilities](https://www.cisa.gov/uscert/ncas/alerts/aa21-356a)
+- [CISA ED 22-02: Apache Log4j Recommended Mitigation Measures](https://www.cisa.gov/uscert/ed-22-02-apache-log4j-recommended-mitigation-measures)
+- [CISA ALERT (AA21-356A): Mitigating Log4Shell and Other Log4j-Related Vulnerabilities](https://www.cisa.gov/uscert/ncas/alerts/aa21-356a)
 - [Emergency Directive 22-02 Mitigate Apache Log4j Vulnerability](https://www.cisa.gov/emergency-directive-22-02)
 - [Statement from CISA Director Easterly on “Log4j” Vulnerability](https://www.cisa.gov/news/2021/12/11/statement-cisa-director-easterly-log4j-vulnerability).
 
@@ -35,17 +36,43 @@ National Vulnerability Database (NVD) Information: [CVE-2021-44228](https://nvd.
 
 ## Mitigation Guidance ##
 
-CISA urges organizations operating products marked as "Fixed" to immediately
-implement listed patches/mitigations [here](https://www.cisa.gov/uscert/apache-log4j-vulnerability-guidance).
+When updates are available, agencies must update software
+using Log4j to the newest version, which is the most
+effective and manageable long-term option. Where
+updating is not possible, the following mitigating
+measures can be considered as a temporary solution
+and apply to the entire solution stack.
 
-CISA urges organizations operating products marked as "Not Fixed" to immediately
-implement alternate controls, including:
+- **Disable Log4j library.** Disabling software using the
+Log4j library is an effective measure, favoring
+controlled downtime over adversary-caused issues.
+This option could cause operational impacts and limit
+visibility into other issues.
+- **Disable JNDI lookups or disable remote codebases.**
+This option, while effective, may involve
+developer work and could impact functionality.
+- **Disconnect affected stacks.** Solution stacks not
+connected to agency networks pose a dramatically
+lower risk from attack. Consider temporarily
+disconnecting the stack from agency networks.
+- **Isolate the system.** Create a “vulnerable network”
+VLAN and segment the solution stack from the
+rest of the enterprise network.
+- **Deploy a properly configured Web Application
+Firewall (WAF) in front of the solution stack.**
+Deploying a WAF is an important, but incomplete,
+solution. While threat actors will be able to
+bypass this mitigation, the reduction in alerting
+will allow an agency SOC to focus on a smaller
+set of alerts.
+- **Apply micropatch.** There are several micropatches
+available. They are not a part of the official
+update but may limit agency risk.
+- Report incidents promptly to CISA and/or the FBI
+[here](https://www.cisa.gov/uscert/report).
 
-- Install a WAF with rules that automatically update.
-- Set `log4j2.formatMsgNoLookups` to true by adding `-Dlog4j2.formatMsgNoLookups=True`
-  to the Java Virtual Machine command for starting your application.
-- Ensure that any alerts from a vulnerable device are immediately actioned.
-- Report incidents promptly to CISA and/or the FBI [here](https://www.cisa.gov/uscert/report).
+For more information regarding CISA recommended mitigation measures please visit
+[here](https://www.cisa.gov/uscert/ed-22-02-apache-log4j-recommended-mitigation-measures).
 
 ## Software List ##