- [Statement from CISA Director Easterly on “Log4j” Vulnerability](https://www.cisa.gov/news/2021/12/11/statement-cisa-director-easterly-log4j-vulnerability).
@ -35,17 +36,16 @@ National Vulnerability Database (NVD) Information: [CVE-2021-44228](https://nvd.
## Mitigation Guidance ##
CISA urges organizations operating products marked as "Fixed" to immediately
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.
- 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).