diff --git a/community/detectors/adselfservice_plus_cve_2021_40539/README.md b/community/detectors/adselfservice_plus_cve_2021_40539/README.md
new file mode 100644
index 000000000..9be472c0e
--- /dev/null
+++ b/community/detectors/adselfservice_plus_cve_2021_40539/README.md
@@ -0,0 +1,19 @@
+# CVE-2021-40539 VulnDetector
+
+This detector checks for ADSelfService Plus REST API Authentication Bypass (RCE)  vulnerability (CVE-2021-40539).
+Zoho ManageEngine ADSelfService Plus version 6113 and prior is vulnerable to REST API authentication bypass with resultant remote code execution.
+
+- https://www.manageengine.com/products/self-service-password/kb/how-to-fix-authentication-bypass-vulnerability-in-REST-API.html
+- https://www.manageengine.com/products/self-service-password/release-notes.html
+- https://www.synacktiv.com/publications/how-to-exploit-cve-2021-40539-on-manageengine-adselfservice-plus.html
+- https://www.rapid7.com/db/vulnerabilities/zoho-manageengine-adselfservice-plus-cve-2021-40539/
+
+## Build jar file for this plugin
+
+Using `gradlew`:
+
+```shell
+./gradlew jar
+```
+
+Tsunami identifiable jar file is located at `build/libs` directory.
diff --git a/community/detectors/adselfservice_plus_cve_2021_40539/build.gradle b/community/detectors/adselfservice_plus_cve_2021_40539/build.gradle
new file mode 100644
index 000000000..324035f74
--- /dev/null
+++ b/community/detectors/adselfservice_plus_cve_2021_40539/build.gradle
@@ -0,0 +1,69 @@
+plugins {
+    id 'java-library'
+}
+
+description = 'Tsunami CVE-2021-40539 VulnDetector plugin.'
+group 'com.google.tsunami'
+version '0.0.1-SNAPSHOT'
+
+
+repositories {
+    maven { // The google mirror is less flaky than mavenCentral()
+        url 'https://maven-central.storage-download.googleapis.com/repos/central/data/'
+    }
+    mavenCentral()
+    mavenLocal()
+}
+
+java {
+    sourceCompatibility = JavaVersion.VERSION_11
+    targetCompatibility = JavaVersion.VERSION_11
+
+    jar.manifest {
+        attributes('Implementation-Title': name,
+                'Implementation-Version': version,
+                'Built-By': System.getProperty('user.name'),
+                'Built-JDK': System.getProperty('java.version'),
+                'Source-Compatibility': sourceCompatibility,
+                'Target-Compatibility': targetCompatibility)
+    }
+
+    javadoc.options {
+        encoding = 'UTF-8'
+        use = true
+        links 'https://docs.oracle.com/javase/8/docs/api/'
+    }
+
+    // Log stacktrace to console when test fails.
+    test {
+        testLogging {
+            exceptionFormat = 'full'
+            showExceptions true
+            showCauses true
+            showStackTraces true
+        }
+        maxHeapSize = '1500m'
+    }
+}
+
+ext {
+    tsunamiVersion = '0.0.7'
+    junitVersion = '4.13'
+    mockitoVersion = '2.28.2'
+    truthVersion = '1.0.1'
+    okhttpVersion = '3.12.0'
+}
+
+dependencies {
+    implementation "com.google.tsunami:tsunami-common:${tsunamiVersion}"
+    implementation "com.google.tsunami:tsunami-plugin:${tsunamiVersion}"
+    implementation "com.google.tsunami:tsunami-proto:${tsunamiVersion}"
+    implementation 'com.google.googlejavaformat:google-java-format:1.13.0'
+
+    testImplementation "junit:junit:${junitVersion}"
+    testImplementation "org.mockito:mockito-core:${mockitoVersion}"
+    testImplementation "com.google.truth:truth:${truthVersion}"
+    testImplementation "com.squareup.okhttp3:mockwebserver:${okhttpVersion}"
+    testImplementation "com.google.truth.extensions:truth-java8-extension:${truthVersion}"
+    testImplementation "com.google.truth.extensions:truth-proto-extension:${truthVersion}"
+}
diff --git a/community/detectors/adselfservice_plus_cve_2021_40539/gradle/wrapper/gradle-wrapper.jar b/community/detectors/adselfservice_plus_cve_2021_40539/gradle/wrapper/gradle-wrapper.jar
new file mode 100644
index 000000000..62d4c0535
Binary files /dev/null and b/community/detectors/adselfservice_plus_cve_2021_40539/gradle/wrapper/gradle-wrapper.jar differ
diff --git a/community/detectors/adselfservice_plus_cve_2021_40539/gradle/wrapper/gradle-wrapper.properties b/community/detectors/adselfservice_plus_cve_2021_40539/gradle/wrapper/gradle-wrapper.properties
new file mode 100644
index 000000000..622ab64a3
--- /dev/null
+++ b/community/detectors/adselfservice_plus_cve_2021_40539/gradle/wrapper/gradle-wrapper.properties
@@ -0,0 +1,5 @@
+distributionBase=GRADLE_USER_HOME
+distributionPath=wrapper/dists
+distributionUrl=https\://services.gradle.org/distributions/gradle-6.5-bin.zip
+zipStoreBase=GRADLE_USER_HOME
+zipStorePath=wrapper/dists
diff --git a/community/detectors/adselfservice_plus_cve_2021_40539/gradlew b/community/detectors/adselfservice_plus_cve_2021_40539/gradlew
new file mode 100755
index 000000000..8f8904743
--- /dev/null
+++ b/community/detectors/adselfservice_plus_cve_2021_40539/gradlew
@@ -0,0 +1,184 @@
+#!/usr/bin/env sh
+
+#
+# Copyright 2015 the original author or authors.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+
+##############################################################################
+##
+##  Gradle start up script for UN*X
+##
+##############################################################################
+
+# Attempt to set APP_HOME
+# Resolve links: $0 may be a link
+PRG="$0"
+# Need this for relative symlinks.
+while [ -h "$PRG" ]; do
+  ls=$(ls -ld "$PRG")
+  link=$(expr "$ls" : '.*-> \(.*\)$')
+  if expr "$link" : '/.*' >/dev/null; then
+    PRG="$link"
+  else
+    PRG=$(dirname "$PRG")"/$link"
+  fi
+done
+SAVED="$(pwd)"
+cd "$(dirname \"$PRG\")/" >/dev/null
+APP_HOME="$(pwd -P)"
+cd "$SAVED" >/dev/null
+
+APP_NAME="Gradle"
+APP_BASE_NAME=$(basename "$0")
+
+# Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
+DEFAULT_JVM_OPTS='"-Xmx64m" "-Xms64m"'
+
+# Use the maximum available, or set MAX_FD != -1 to use that value.
+MAX_FD="maximum"
+
+warn() {
+  echo "$*"
+}
+
+die() {
+  echo
+  echo "$*"
+  echo
+  exit 1
+}
+
+# OS specific support (must be 'true' or 'false').
+cygwin=false
+msys=false
+darwin=false
+nonstop=false
+case "$(uname)" in
+CYGWIN*)
+  cygwin=true
+  ;;
+Darwin*)
+  darwin=true
+  ;;
+MINGW*)
+  msys=true
+  ;;
+NONSTOP*)
+  nonstop=true
+  ;;
+esac
+
+CLASSPATH=$APP_HOME/gradle/wrapper/gradle-wrapper.jar
+
+# Determine the Java command to use to start the JVM.
+if [ -n "$JAVA_HOME" ]; then
+  if [ -x "$JAVA_HOME/jre/sh/java" ]; then
+    # IBM's JDK on AIX uses strange locations for the executables
+    JAVACMD="$JAVA_HOME/jre/sh/java"
+  else
+    JAVACMD="$JAVA_HOME/bin/java"
+  fi
+  if [ ! -x "$JAVACMD" ]; then
+    die "ERROR: JAVA_HOME is set to an invalid directory: $JAVA_HOME
+
+Please set the JAVA_HOME variable in your environment to match the
+location of your Java installation."
+  fi
+else
+  JAVACMD="java"
+  which java >/dev/null 2>&1 || die "ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
+
+Please set the JAVA_HOME variable in your environment to match the
+location of your Java installation."
+fi
+
+# Increase the maximum file descriptors if we can.
+if [ "$cygwin" = "false" -a "$darwin" = "false" -a "$nonstop" = "false" ]; then
+  MAX_FD_LIMIT=$(ulimit -H -n)
+  if [ $? -eq 0 ]; then
+    if [ "$MAX_FD" = "maximum" -o "$MAX_FD" = "max" ]; then
+      MAX_FD="$MAX_FD_LIMIT"
+    fi
+    ulimit -n $MAX_FD
+    if [ $? -ne 0 ]; then
+      warn "Could not set maximum file descriptor limit: $MAX_FD"
+    fi
+  else
+    warn "Could not query maximum file descriptor limit: $MAX_FD_LIMIT"
+  fi
+fi
+
+# For Darwin, add options to specify how the application appears in the dock
+if $darwin; then
+  GRADLE_OPTS="$GRADLE_OPTS \"-Xdock:name=$APP_NAME\" \"-Xdock:icon=$APP_HOME/media/gradle.icns\""
+fi
+
+# For Cygwin or MSYS, switch paths to Windows format before running java
+if [ "$cygwin" = "true" -o "$msys" = "true" ]; then
+  APP_HOME=$(cygpath --path --mixed "$APP_HOME")
+  CLASSPATH=$(cygpath --path --mixed "$CLASSPATH")
+
+  JAVACMD=$(cygpath --unix "$JAVACMD")
+
+  # We build the pattern for arguments to be converted via cygpath
+  ROOTDIRSRAW=$(find -L / -maxdepth 1 -mindepth 1 -type d 2>/dev/null)
+  SEP=""
+  for dir in $ROOTDIRSRAW; do
+    ROOTDIRS="$ROOTDIRS$SEP$dir"
+    SEP="|"
+  done
+  OURCYGPATTERN="(^($ROOTDIRS))"
+  # Add a user-defined pattern to the cygpath arguments
+  if [ "$GRADLE_CYGPATTERN" != "" ]; then
+    OURCYGPATTERN="$OURCYGPATTERN|($GRADLE_CYGPATTERN)"
+  fi
+  # Now convert the arguments - kludge to limit ourselves to /bin/sh
+  i=0
+  for arg in "$@"; do
+    CHECK=$(echo "$arg" | egrep -c "$OURCYGPATTERN" -)
+    CHECK2=$(echo "$arg" | egrep -c "^-") ### Determine if an option
+
+    if [ $CHECK -ne 0 ] && [ $CHECK2 -eq 0 ]; then ### Added a condition
+      eval $(echo args$i)=$(cygpath --path --ignore --mixed "$arg")
+    else
+      eval $(echo args$i)="\"$arg\""
+    fi
+    i=$(expr $i + 1)
+  done
+  case $i in
+  0) set -- ;;
+  1) set -- "$args0" ;;
+  2) set -- "$args0" "$args1" ;;
+  3) set -- "$args0" "$args1" "$args2" ;;
+  4) set -- "$args0" "$args1" "$args2" "$args3" ;;
+  5) set -- "$args0" "$args1" "$args2" "$args3" "$args4" ;;
+  6) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" ;;
+  7) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" ;;
+  8) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" "$args7" ;;
+  9) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" "$args7" "$args8" ;;
+  esac
+fi
+
+# Escape application args
+save() {
+  for i; do printf %s\\n "$i" | sed "s/'/'\\\\''/g;1s/^/'/;\$s/\$/' \\\\/"; done
+  echo " "
+}
+APP_ARGS=$(save "$@")
+
+# Collect all arguments for the java command, following the shell quoting and substitution rules
+eval set -- $DEFAULT_JVM_OPTS $JAVA_OPTS $GRADLE_OPTS "\"-Dorg.gradle.appname=$APP_BASE_NAME\"" -classpath "\"$CLASSPATH\"" org.gradle.wrapper.GradleWrapperMain "$APP_ARGS"
+
+exec "$JAVACMD" "$@"
diff --git a/community/detectors/adselfservice_plus_cve_2021_40539/gradlew.bat b/community/detectors/adselfservice_plus_cve_2021_40539/gradlew.bat
new file mode 100644
index 000000000..5093609d5
--- /dev/null
+++ b/community/detectors/adselfservice_plus_cve_2021_40539/gradlew.bat
@@ -0,0 +1,104 @@
+@rem
+@rem Copyright 2015 the original author or authors.
+@rem
+@rem Licensed under the Apache License, Version 2.0 (the "License");
+@rem you may not use this file except in compliance with the License.
+@rem You may obtain a copy of the License at
+@rem
+@rem      https://www.apache.org/licenses/LICENSE-2.0
+@rem
+@rem Unless required by applicable law or agreed to in writing, software
+@rem distributed under the License is distributed on an "AS IS" BASIS,
+@rem WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+@rem See the License for the specific language governing permissions and
+@rem limitations under the License.
+@rem
+
+@if "%DEBUG%" == "" @echo off
+@rem ##########################################################################
+@rem
+@rem  Gradle startup script for Windows
+@rem
+@rem ##########################################################################
+
+@rem Set local scope for the variables with windows NT shell
+if "%OS%"=="Windows_NT" setlocal
+
+set DIRNAME=%~dp0
+if "%DIRNAME%" == "" set DIRNAME=.
+set APP_BASE_NAME=%~n0
+set APP_HOME=%DIRNAME%
+
+@rem Resolve any "." and ".." in APP_HOME to make it shorter.
+for %%i in ("%APP_HOME%") do set APP_HOME=%%~fi
+
+@rem Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
+set DEFAULT_JVM_OPTS="-Xmx64m" "-Xms64m"
+
+@rem Find java.exe
+if defined JAVA_HOME goto findJavaFromJavaHome
+
+set JAVA_EXE=java.exe
+%JAVA_EXE% -version >NUL 2>&1
+if "%ERRORLEVEL%" == "0" goto init
+
+echo.
+echo ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
+echo.
+echo Please set the JAVA_HOME variable in your environment to match the
+echo location of your Java installation.
+
+goto fail
+
+:findJavaFromJavaHome
+set JAVA_HOME=%JAVA_HOME:"=%
+set JAVA_EXE=%JAVA_HOME%/bin/java.exe
+
+if exist "%JAVA_EXE%" goto init
+
+echo.
+echo ERROR: JAVA_HOME is set to an invalid directory: %JAVA_HOME%
+echo.
+echo Please set the JAVA_HOME variable in your environment to match the
+echo location of your Java installation.
+
+goto fail
+
+:init
+@rem Get command-line arguments, handling Windows variants
+
+if not "%OS%" == "Windows_NT" goto win9xME_args
+
+:win9xME_args
+@rem Slurp the command line arguments.
+set CMD_LINE_ARGS=
+set _SKIP=2
+
+:win9xME_args_slurp
+if "x%~1" == "x" goto execute
+
+set CMD_LINE_ARGS=%*
+
+:execute
+@rem Setup the command line
+
+set CLASSPATH=%APP_HOME%\gradle\wrapper\gradle-wrapper.jar
+
+
+@rem Execute Gradle
+"%JAVA_EXE%" %DEFAULT_JVM_OPTS% %JAVA_OPTS% %GRADLE_OPTS% "-Dorg.gradle.appname=%APP_BASE_NAME%" -classpath "%CLASSPATH%" org.gradle.wrapper.GradleWrapperMain %CMD_LINE_ARGS%
+
+:end
+@rem End local scope for the variables with windows NT shell
+if "%ERRORLEVEL%"=="0" goto mainEnd
+
+:fail
+rem Set variable GRADLE_EXIT_CONSOLE if you need the _script_ return code instead of
+rem the _cmd.exe /c_ return code!
+if  not "" == "%GRADLE_EXIT_CONSOLE%" exit 1
+exit /b 1
+
+:mainEnd
+if "%OS%"=="Windows_NT" endlocal
+
+:omega
diff --git a/community/detectors/adselfservice_plus_cve_2021_40539/settings.gradle b/community/detectors/adselfservice_plus_cve_2021_40539/settings.gradle
new file mode 100644
index 000000000..afe1fdaeb
--- /dev/null
+++ b/community/detectors/adselfservice_plus_cve_2021_40539/settings.gradle
@@ -0,0 +1 @@
+rootProject.name = 'CVE-2021-40539'
diff --git a/community/detectors/adselfservice_plus_cve_2021_40539/src/main/java/com/google/tsunami/plugins/detectors/cves/cve202140539/Cve202140539DetectorBootstrapModule.java b/community/detectors/adselfservice_plus_cve_2021_40539/src/main/java/com/google/tsunami/plugins/detectors/cves/cve202140539/Cve202140539DetectorBootstrapModule.java
new file mode 100644
index 000000000..31e01ff6a
--- /dev/null
+++ b/community/detectors/adselfservice_plus_cve_2021_40539/src/main/java/com/google/tsunami/plugins/detectors/cves/cve202140539/Cve202140539DetectorBootstrapModule.java
@@ -0,0 +1,29 @@
+/*
+ * Copyright 2021 Google LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.google.tsunami.plugins.detectors.cves.cve202140539;
+
+import com.google.tsunami.plugin.PluginBootstrapModule;
+
+/**
+ * An CVE-2021-40539 Guice module that bootstraps the {@link Cve202140539VulnDetector}.
+ */
+public final class Cve202140539DetectorBootstrapModule extends PluginBootstrapModule {
+
+  @Override
+  protected void configurePlugin() {
+    registerPlugin(Cve202140539VulnDetector.class);
+  }
+}
diff --git a/community/detectors/adselfservice_plus_cve_2021_40539/src/main/java/com/google/tsunami/plugins/detectors/cves/cve202140539/Cve202140539VulnDetector.java b/community/detectors/adselfservice_plus_cve_2021_40539/src/main/java/com/google/tsunami/plugins/detectors/cves/cve202140539/Cve202140539VulnDetector.java
new file mode 100644
index 000000000..11b0df7d9
--- /dev/null
+++ b/community/detectors/adselfservice_plus_cve_2021_40539/src/main/java/com/google/tsunami/plugins/detectors/cves/cve202140539/Cve202140539VulnDetector.java
@@ -0,0 +1,171 @@
+/*
+ * Copyright 2021 Google LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.google.tsunami.plugins.detectors.cves.cve202140539;
+
+import static com.google.common.base.Preconditions.checkNotNull;
+import static com.google.common.collect.ImmutableList.toImmutableList;
+import static com.google.common.net.HttpHeaders.CONTENT_TYPE;
+import static com.google.tsunami.common.data.NetworkEndpointUtils.toUriAuthority;
+import static com.google.tsunami.common.net.http.HttpRequest.post;
+
+import com.google.common.annotations.VisibleForTesting;
+import com.google.common.collect.ImmutableList;
+import com.google.common.flogger.GoogleLogger;
+import com.google.common.net.MediaType;
+import com.google.protobuf.ByteString;
+import com.google.protobuf.util.Timestamps;
+import com.google.tsunami.common.data.NetworkServiceUtils;
+import com.google.tsunami.common.net.http.HttpClient;
+import com.google.tsunami.common.net.http.HttpHeaders;
+import com.google.tsunami.common.net.http.HttpResponse;
+import com.google.tsunami.common.time.UtcClock;
+import com.google.tsunami.plugin.PluginType;
+import com.google.tsunami.plugin.VulnDetector;
+import com.google.tsunami.plugin.annotations.PluginInfo;
+import com.google.tsunami.proto.DetectionReport;
+import com.google.tsunami.proto.DetectionReportList;
+import com.google.tsunami.proto.DetectionStatus;
+import com.google.tsunami.proto.NetworkService;
+import com.google.tsunami.proto.Severity;
+import com.google.tsunami.proto.TargetInfo;
+import com.google.tsunami.proto.Vulnerability;
+import com.google.tsunami.proto.VulnerabilityId;
+import java.io.IOException;
+import java.time.Clock;
+import java.time.Instant;
+import javax.inject.Inject;
+
+/** A {@link VulnDetector} that detects the CVE-2021-40539 vulnerability. */
+@PluginInfo(
+    type = PluginType.VULN_DETECTION,
+    name = "CVE202140539VulnDetector",
+    version = "0.1",
+    description = Cve202140539VulnDetector.VULN_DESCRIPTION,
+    author = "hh-hunter",
+    bootstrapModule = Cve202140539DetectorBootstrapModule.class)
+public final class Cve202140539VulnDetector implements VulnDetector {
+
+  @VisibleForTesting
+  static final String DETECTION_STRING = "<script type=\"text/javascript\">var d = new Date();";
+
+  @VisibleForTesting
+  static final String VULN_DESCRIPTION =
+      "Zoho ManageEngine ADSelfService Plus version 6113 and prior is vulnerable to REST API "
+          + "authentication bypass with resultant remote code execution.";
+
+  private static final GoogleLogger logger = GoogleLogger.forEnclosingClass();
+
+  private static final String VUL_PATH = "./RestAPI/LogonCustomization";
+
+  private static final String POST_DATA = "methodToCall=previewMobLogo";
+
+  private final HttpClient httpClient;
+
+  private final Clock utcClock;
+
+  @Inject
+  Cve202140539VulnDetector(@UtcClock Clock utcClock, HttpClient httpClient) {
+    this.httpClient = checkNotNull(httpClient);
+    this.utcClock = checkNotNull(utcClock);
+  }
+
+  private static boolean isWebServiceOrUnknownService(NetworkService networkService) {
+    return networkService.getServiceName().isEmpty()
+        || NetworkServiceUtils.isWebService(networkService)
+        || NetworkServiceUtils.getServiceName(networkService).equals("sun-answerbook");
+  }
+
+  private static StringBuilder buildTarget(NetworkService networkService) {
+    StringBuilder targetUrlBuilder = new StringBuilder();
+    if (NetworkServiceUtils.isWebService(networkService)) {
+      targetUrlBuilder.append(NetworkServiceUtils.buildWebApplicationRootUrl(networkService));
+    } else {
+      targetUrlBuilder
+          .append("http://")
+          .append(toUriAuthority(networkService.getNetworkEndpoint()))
+          .append("/");
+    }
+    targetUrlBuilder.append(VUL_PATH);
+    return targetUrlBuilder;
+  }
+
+  @Override
+  public DetectionReportList detect(
+      TargetInfo targetInfo, ImmutableList<NetworkService> matchedServices) {
+    logger.atInfo().log("CVE-2921-40539 starts detecting.");
+
+    return DetectionReportList.newBuilder()
+        .addAllDetectionReports(
+            matchedServices.stream()
+                .filter(Cve202140539VulnDetector::isWebServiceOrUnknownService)
+                .filter(this::isServiceVulnerable)
+                .map(networkService -> buildDetectionReport(targetInfo, networkService))
+                .collect(toImmutableList()))
+        .build();
+  }
+
+  private boolean isServiceVulnerable(NetworkService networkService) {
+    String targetVulnerabilityUrl = buildTarget(networkService).toString();
+    try {
+      HttpResponse httpResponse =
+          httpClient.sendAsIs(
+              post(targetVulnerabilityUrl)
+                  .setHeaders(
+                      HttpHeaders.builder()
+                          .addHeader(CONTENT_TYPE, MediaType.FORM_DATA.toString())
+                          .build())
+                  .setRequestBody(ByteString.copyFromUtf8(POST_DATA))
+                  .build());
+      if (httpResponse.status().code() == 200
+          && httpResponse.bodyString().get().contains(DETECTION_STRING)) {
+        return true;
+      }
+    } catch (IOException | AssertionError e) {
+      logger.atWarning().withCause(e).log("Request to target %s failed", networkService);
+      return false;
+    }
+    return false;
+  }
+
+  private DetectionReport buildDetectionReport(
+      TargetInfo targetInfo, NetworkService vulnerableNetworkService) {
+    return DetectionReport.newBuilder()
+        .setTargetInfo(targetInfo)
+        .setNetworkService(vulnerableNetworkService)
+        .setDetectionTimestamp(Timestamps.fromMillis(Instant.now(utcClock).toEpochMilli()))
+        .setDetectionStatus(DetectionStatus.VULNERABILITY_VERIFIED)
+        .setVulnerability(
+            Vulnerability.newBuilder()
+                .setMainId(
+                    VulnerabilityId.newBuilder()
+                        .setPublisher("TSUNAMI_COMMUNITY")
+                        .setValue("CVE_2021_40539"))
+                .setSeverity(Severity.CRITICAL)
+                .setTitle("CVE-2021-40539 ADSelfService Plus REST API Authentication Bypass (RCE)")
+                .setRecommendation(
+                    "1. Disconnect the affected system from your network.\n2. Back up the "
+                        + "ADSelfService Plus database using these steps.\n3. Format the "
+                        + "compromised machine. \n4. Download and install ADSelfService Plus. \n"
+                        + "5. Restore the backup and start the server.\n6. Once the server is up "
+                        + "and running, update ADSelfService Plus to the latest build, 6114, using"
+                        + " the service pack.\n7. Check for unauthorized access or use of accounts."
+                        + " Also, check for any evidences of lateral movement from the compromised"
+                        + " machine to other machines. If there are any indications of compromised"
+                        + " Active Directory accounts, initiate password reset for those accounts.")
+                .setDescription(VULN_DESCRIPTION))
+        .build();
+  }
+}
diff --git a/community/detectors/adselfservice_plus_cve_2021_40539/src/test/java/com/google/tsunami/plugins/detectors/cves/cve202140539/Cve202140539VulnDetectorTest.java b/community/detectors/adselfservice_plus_cve_2021_40539/src/test/java/com/google/tsunami/plugins/detectors/cves/cve202140539/Cve202140539VulnDetectorTest.java
new file mode 100644
index 000000000..af8205d40
--- /dev/null
+++ b/community/detectors/adselfservice_plus_cve_2021_40539/src/test/java/com/google/tsunami/plugins/detectors/cves/cve202140539/Cve202140539VulnDetectorTest.java
@@ -0,0 +1,153 @@
+/*
+ * Copyright 2021 Google LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.google.tsunami.plugins.detectors.cves.cve202140539;
+
+import static com.google.common.truth.extensions.proto.ProtoTruth.assertThat;
+import static com.google.tsunami.common.data.NetworkEndpointUtils.forHostname;
+import static com.google.tsunami.common.data.NetworkEndpointUtils.forHostnameAndPort;
+import static com.google.tsunami.plugins.detectors.cves.cve202140539.Cve202140539VulnDetector.DETECTION_STRING;
+
+import com.google.common.collect.ImmutableList;
+import com.google.inject.Guice;
+import com.google.protobuf.util.Timestamps;
+import com.google.tsunami.common.net.http.HttpClientModule;
+import com.google.tsunami.common.time.testing.FakeUtcClock;
+import com.google.tsunami.common.time.testing.FakeUtcClockModule;
+import com.google.tsunami.proto.DetectionReport;
+import com.google.tsunami.proto.DetectionReportList;
+import com.google.tsunami.proto.DetectionStatus;
+import com.google.tsunami.proto.NetworkService;
+import com.google.tsunami.proto.Severity;
+import com.google.tsunami.proto.Software;
+import com.google.tsunami.proto.TargetInfo;
+import com.google.tsunami.proto.TransportProtocol;
+import com.google.tsunami.proto.Vulnerability;
+import com.google.tsunami.proto.VulnerabilityId;
+import java.io.IOException;
+import java.time.Instant;
+import javax.inject.Inject;
+import okhttp3.mockwebserver.MockResponse;
+import okhttp3.mockwebserver.MockWebServer;
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.junit.runners.JUnit4;
+
+/** Unit tests for {@link Cve202140539VulnDetector}. */
+@RunWith(JUnit4.class)
+public final class Cve202140539VulnDetectorTest {
+
+  private final FakeUtcClock fakeUtcClock =
+      FakeUtcClock.create().setNow(Instant.parse("2020-01-01T00:00:00.00Z"));
+
+  @Inject private Cve202140539VulnDetector detector;
+
+  private MockWebServer mockWebServer;
+
+  @Before
+  public void setUp() {
+    mockWebServer = new MockWebServer();
+    Guice.createInjector(
+            new FakeUtcClockModule(fakeUtcClock),
+            new Cve202140539DetectorBootstrapModule(),
+            new HttpClientModule.Builder().build())
+        .injectMembers(this);
+  }
+
+  @After
+  public void tearDown() throws IOException {
+    mockWebServer.shutdown();
+  }
+
+  @Test
+  public void detect_whenVulnerable_returnsVulnerability() throws IOException {
+    mockWebResponse(DETECTION_STRING);
+    NetworkService service =
+        NetworkService.newBuilder()
+            .setNetworkEndpoint(
+                forHostnameAndPort(mockWebServer.getHostName(), mockWebServer.getPort()))
+            .setTransportProtocol(TransportProtocol.TCP)
+            .setSoftware(Software.newBuilder().setName("http"))
+            .setServiceName("http")
+            .build();
+    TargetInfo targetInfo =
+        TargetInfo.newBuilder()
+            .addNetworkEndpoints(forHostname(mockWebServer.getHostName()))
+            .build();
+
+    DetectionReportList detectionReports = detector.detect(targetInfo, ImmutableList.of(service));
+
+    assertThat(detectionReports.getDetectionReportsList())
+        .containsExactly(
+            DetectionReport.newBuilder()
+                .setTargetInfo(targetInfo)
+                .setNetworkService(service)
+                .setDetectionTimestamp(
+                    Timestamps.fromMillis(Instant.now(fakeUtcClock).toEpochMilli()))
+                .setDetectionStatus(DetectionStatus.VULNERABILITY_VERIFIED)
+                .setVulnerability(
+                    Vulnerability.newBuilder()
+                        .setMainId(
+                            VulnerabilityId.newBuilder()
+                                .setPublisher("TSUNAMI_COMMUNITY")
+                                .setValue("CVE_2021_40539"))
+                        .setSeverity(Severity.CRITICAL)
+                        .setTitle(
+                            "CVE-2021-40539 ADSelfService Plus REST API Authentication Bypass "
+                                + "(RCE)")
+                        .setRecommendation(
+                            "1. Disconnect the affected system from your network.\n2. Back up the "
+                                + "ADSelfService Plus database using these steps.\n3. Format the "
+                                + "compromised machine. \n4. Download and install ADSelfService "
+                                + "Plus. \n5. Restore the backup and start the server.\n6. Once the"
+                                + " server is up and running, update ADSelfService Plus to the "
+                                + "latest build, 6114, using the service pack.\n7. Check for "
+                                + "unauthorized access or use of accounts. Also, check for any "
+                                + "evidences of lateral movement from the compromised machine to "
+                                + "other machines. If there are any indications of compromised "
+                                + "Active Directory accounts, initiate password reset for those "
+                                + "accounts.")
+                        .setDescription(Cve202140539VulnDetector.VULN_DESCRIPTION))
+                .build());
+  }
+
+  @Test
+  public void detect_whenNotVulnerable_returnsNoVulnerability() throws IOException {
+    mockWebResponse("Hello World");
+    ImmutableList<NetworkService> httpServices =
+        ImmutableList.of(
+            NetworkService.newBuilder()
+                .setNetworkEndpoint(
+                    forHostnameAndPort(mockWebServer.getHostName(), mockWebServer.getPort()))
+                .setTransportProtocol(TransportProtocol.TCP)
+                .setServiceName("http")
+                .build());
+    TargetInfo targetInfo =
+        TargetInfo.newBuilder()
+            .addNetworkEndpoints(forHostname(mockWebServer.getHostName()))
+            .build();
+
+    DetectionReportList detectionReports = detector.detect(targetInfo, httpServices);
+
+    assertThat(detectionReports.getDetectionReportsList()).isEmpty();
+  }
+
+  private void mockWebResponse(String body) throws IOException {
+    mockWebServer.enqueue(new MockResponse().setResponseCode(200).setBody(body));
+    mockWebServer.start();
+  }
+}