Versions of the Amazon AWS Apache Log4j hotpatch package before log4j-cve-2021-44228-hotpatch-1.3.5 are affected by a race condition that could lead to a local privilege escalation. This Hotpatch package is not a replacement for updating to a log4j version that mitigates CVE-2021-44228 or CVE-2021-45046; it provides a temporary mitigation to CVE-2021-44228 by hotpatching the local Java virtual machines. To do so, it iterates through all running Java processes, performs several checks, and executes the Java virtual machine with the same permissions and capabilities as the running process to load the hotpatch. A local user could cause the hotpatch script to execute a binary with elevated privileges by running a custom java process that performs exec() of an SUID binary after the hotpatch has observed the process path and before it has observed its effective user ID.

Incomplete fix for CVE-2021-3100. The Apache Log4j hotpatch package starting with log4j-cve-2021-44228-hotpatch-1.1-16 will now explicitly mimic the Linux capabilities and cgroups of the target Java process that the hotpatch is applied to.

The Apache Log4j hotpatch package before log4j-cve-2021-44228-hotpatch-1.1-13 didn’t mimic the permissions of the JVM being patched, allowing it to escalate privileges.