build: update log4j version to 2.13.2
diff --git a/pom.xml b/pom.xml
index 13ed06a..7114b92 100644
--- a/pom.xml
+++ b/pom.xml
@@ -57,7 +57,7 @@
     <javadoc.plugin.version>2.10.3</javadoc.plugin.version>
     <jxr.plugin.version>2.5</jxr.plugin.version>
     <kotlin.version>1.3.0</kotlin.version>
-    <log4j.version>2.11.0</log4j.version>
+    <log4j.version>2.13.2</log4j.version>
     <pmd.plugin.version>3.8</pmd.plugin.version>
     <rat.plugin.version>0.12</rat.plugin.version>
     <site.plugin.version>3.4</site.plugin.version>