diff --git a/distribution/server/src/assemble/LICENSE.bin.txt b/distribution/server/src/assemble/LICENSE.bin.txt
index 936528ad8b7e2..d4c8f0a9b2ff4 100644
--- a/distribution/server/src/assemble/LICENSE.bin.txt
+++ b/distribution/server/src/assemble/LICENSE.bin.txt
@@ -388,11 +388,11 @@ The Apache Software License, Version 2.0
     - jakarta.validation-jakarta.validation-api-2.0.2.jar
     - javax.validation-validation-api-1.1.0.Final.jar
  * Log4J
-    - org.apache.logging.log4j-log4j-api-2.17.1.jar
-    - org.apache.logging.log4j-log4j-core-2.17.1.jar
-    - org.apache.logging.log4j-log4j-slf4j-impl-2.17.1.jar
-    - org.apache.logging.log4j-log4j-web-2.17.1.jar
-    - org.apache.logging.log4j-log4j-1.2-api-2.17.1.jar
+    - org.apache.logging.log4j-log4j-api-2.18.0.jar
+    - org.apache.logging.log4j-log4j-core-2.18.0.jar
+    - org.apache.logging.log4j-log4j-slf4j-impl-2.18.0.jar
+    - org.apache.logging.log4j-log4j-web-2.18.0.jar
+    - org.apache.logging.log4j-log4j-1.2-api-2.18.0.jar
  * Java Native Access JNA -- net.java.dev.jna-jna-4.2.0.jar
  * BookKeeper
     - org.apache.bookkeeper-bookkeeper-common-4.12.1.jar
diff --git a/pom.xml b/pom.xml
index e793d8998b7bf..867afadbf673d 100644
--- a/pom.xml
+++ b/pom.xml
@@ -111,7 +111,7 @@ flexible messaging model and an intuitive client API.</description>
     <rocksdb.version>6.10.2</rocksdb.version>
     <slf4j.version>1.7.25</slf4j.version>
     <commons.collections.version>3.2.2</commons.collections.version>
-    <log4j2.version>2.17.1</log4j2.version>
+    <log4j2.version>2.18.0</log4j2.version>
     <bouncycastle.version>1.68</bouncycastle.version>
     <bouncycastlefips.version>1.0.2</bouncycastlefips.version>
     <jackson.version>2.11.1</jackson.version>
@@ -127,6 +127,7 @@ flexible messaging model and an intuitive client API.</description>
     <grpc.version>1.18.0</grpc.version>
     <protoc-gen-grpc-java.version>${grpc.version}</protoc-gen-grpc-java.version>
     <gson.version>2.8.9</gson.version>
+    <system-lambda.version>1.2.1</system-lambda.version>
     <sketches.version>0.8.3</sketches.version>
     <hbc-core.version>2.2.0</hbc-core.version>
     <cassandra-driver-core.version>3.6.0</cassandra-driver-core.version>
@@ -996,6 +997,13 @@ flexible messaging model and an intuitive client API.</description>
       <scope>test</scope>
     </dependency>
 
+    <dependency>
+      <groupId>com.github.stefanbirkner</groupId>
+      <artifactId>system-lambda</artifactId>
+      <version>${system-lambda.version}</version>
+      <scope>test</scope>
+    </dependency>
+
     <dependency>
       <groupId>org.powermock</groupId>
       <artifactId>powermock-module-testng</artifactId>
diff --git a/pulsar-functions/secrets/src/test/java/org/apache/pulsar/functions/secretsprovider/EnvironmentBasedSecretsProviderTest.java b/pulsar-functions/secrets/src/test/java/org/apache/pulsar/functions/secretsprovider/EnvironmentBasedSecretsProviderTest.java
index 1fc76b337a5fd..ef4d41ee80cad 100644
--- a/pulsar-functions/secrets/src/test/java/org/apache/pulsar/functions/secretsprovider/EnvironmentBasedSecretsProviderTest.java
+++ b/pulsar-functions/secrets/src/test/java/org/apache/pulsar/functions/secretsprovider/EnvironmentBasedSecretsProviderTest.java
@@ -21,10 +21,7 @@
 
 import static org.testng.Assert.assertEquals;
 import static org.testng.Assert.assertNull;
-
-import java.lang.reflect.Field;
-import java.util.Map;
-
+import com.github.stefanbirkner.systemlambda.SystemLambda;
 import org.testng.annotations.Test;
 
 public class EnvironmentBasedSecretsProviderTest {
@@ -32,38 +29,9 @@ public class EnvironmentBasedSecretsProviderTest {
     public void testConfigValidation() throws Exception {
         EnvironmentBasedSecretsProvider provider = new EnvironmentBasedSecretsProvider();
         assertNull(provider.provideSecret("mySecretName", "Ignored"));
-        injectEnvironmentVariable("mySecretName", "SecretValue");
-        assertEquals(provider.provideSecret("mySecretName", "Ignored"), "SecretValue");
-    }
-
-    private static void injectEnvironmentVariable(String key, String value)
-            throws Exception {
-
-        Class<?> processEnvironment = Class.forName("java.lang.ProcessEnvironment");
-
-        Field unmodifiableMapField = getAccessibleField(processEnvironment, "theUnmodifiableEnvironment");
-        Object unmodifiableMap = unmodifiableMapField.get(null);
-        injectIntoUnmodifiableMap(key, value, unmodifiableMap);
-
-        Field mapField = getAccessibleField(processEnvironment, "theEnvironment");
-        Map<String, String> map = (Map<String, String>) mapField.get(null);
-        map.put(key, value);
-    }
-
-    private static Field getAccessibleField(Class<?> clazz, String fieldName)
-            throws NoSuchFieldException {
-
-        Field field = clazz.getDeclaredField(fieldName);
-        field.setAccessible(true);
-        return field;
+        SystemLambda.withEnvironmentVariable("mySecretName", "SecretValue").execute(() -> {
+            assertEquals(provider.provideSecret("mySecretName", "Ignored"), "SecretValue");
+        });
     }
 
-    private static void injectIntoUnmodifiableMap(String key, String value, Object map)
-            throws ReflectiveOperationException {
-
-        Class unmodifiableMap = Class.forName("java.util.Collections$UnmodifiableMap");
-        Field field = getAccessibleField(unmodifiableMap, "m");
-        Object obj = field.get(map);
-        ((Map<String, String>) obj).put(key, value);
-    }
 }
diff --git a/pulsar-io/flume/src/test/java/org/apache/pulsar/io/flume/node/TestEnvVarResolverProperties.java b/pulsar-io/flume/src/test/java/org/apache/pulsar/io/flume/node/TestEnvVarResolverProperties.java
index dc62c2bef70ad..f826da92d801f 100644
--- a/pulsar-io/flume/src/test/java/org/apache/pulsar/io/flume/node/TestEnvVarResolverProperties.java
+++ b/pulsar-io/flume/src/test/java/org/apache/pulsar/io/flume/node/TestEnvVarResolverProperties.java
@@ -18,16 +18,16 @@
  */
 package org.apache.pulsar.io.flume.node;
 
-import junit.framework.Assert;
+import static org.testng.Assert.assertEquals;
+import com.github.stefanbirkner.systemlambda.SystemLambda;
+import java.io.File;
 import org.junit.Before;
 import org.junit.Rule;
 import org.junit.Test;
 import org.junit.contrib.java.lang.system.EnvironmentVariables;
 
-import java.io.File;
-
-public class TestEnvVarResolverProperties {
-    private static final File TESTFILE = new File(
+public final class TestEnvVarResolverProperties {
+    private static final File TEST_FILE = new File(
             TestEnvVarResolverProperties.class.getClassLoader()
                     .getResource("flume-conf-with-envvars.properties").getFile());
 
@@ -36,35 +36,38 @@ public class TestEnvVarResolverProperties {
     private PropertiesFileConfigurationProvider provider;
 
     @Before
-    public void setUp() throws Exception {
-        provider = new PropertiesFileConfigurationProvider("a1", TESTFILE);
+    public void setUp() {
+        provider = new PropertiesFileConfigurationProvider("a1", TEST_FILE);
     }
 
     @Test
     public void resolveEnvVar() throws Exception {
-        environmentVariables.set("VARNAME", "varvalue");
-        String resolved = EnvVarResolverProperties.resolveEnvVars("padding ${VARNAME} padding");
-        Assert.assertEquals("padding varvalue padding", resolved);
+        SystemLambda.withEnvironmentVariable("VARNAME", "varvalue").execute(() -> {
+            String resolved = EnvVarResolverProperties.resolveEnvVars("padding ${VARNAME} padding");
+            assertEquals(resolved, "padding varvalue padding");
+        });
     }
 
     @Test
     public void resolveEnvVars() throws Exception {
-        environmentVariables.set("VARNAME1", "varvalue1");
-        environmentVariables.set("VARNAME2", "varvalue2");
-        String resolved = EnvVarResolverProperties
-                .resolveEnvVars("padding ${VARNAME1} ${VARNAME2} padding");
-        Assert.assertEquals("padding varvalue1 varvalue2 padding", resolved);
+        SystemLambda.withEnvironmentVariable("VARNAME1", "varvalue1")
+                .and("VARNAME2", "varvalue2")
+                .execute(() -> {
+                    String resolved = EnvVarResolverProperties.resolveEnvVars(
+                            "padding ${VARNAME1} ${VARNAME2} padding");
+                    assertEquals(resolved, "padding varvalue1 varvalue2 padding");
+                });
     }
 
     @Test
     public void getProperty() throws Exception {
-        String NC_PORT = "6667";
-        environmentVariables.set("NC_PORT", NC_PORT);
-        System.setProperty("propertiesImplementation",
-                "org.apache.pulsar.io.flume.node.EnvVarResolverProperties");
+        SystemLambda.withEnvironmentVariable("NC_PORT", "6667").execute(() -> {
+            System.setProperty("propertiesImplementation",
+                    "org.apache.pulsar.io.flume.node.EnvVarResolverProperties");
 
-        Assert.assertEquals(NC_PORT, provider.getFlumeConfiguration()
-                .getConfigurationFor("a1")
-                .getSourceContext().get("r1").getParameters().get("port"));
+            assertEquals(provider.getFlumeConfiguration()
+                    .getConfigurationFor("a1")
+                    .getSourceContext().get("r1").getParameters().get("port"), "6667");
+        });
     }
-}
+}
\ No newline at end of file