chain17

agent17

依赖如下，给了一个入口的hessian2反序列化，题目自己给了一个Bean，其中的getter可以触发原生反序列化，不过存在很多黑名单

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<dependency>
	<groupId>com.alibaba</groupId>
	<artifactId>hessian-lite</artifactId>
	<version>3.2.13</version>
</dependency>

<dependency>
	<groupId>cn.hutool</groupId>
	<artifactId>hutool-all</artifactId>
	<version>5.8.16</version>
</dependency>

<!-- https://mvnrepository.com/artifact/com.h2database/h2 -->
<dependency>
	<groupId>com.h2database</groupId>
	<artifactId>h2</artifactId>
	<version>2.2.224</version>
</dependency>

hessian反序列化

首先想到的是入口的hessian反序列化，本题的hessian-lite版本为3.2.13，在3.2.12可以通过HashMap到Xstring来触发toString，最后调用到getter从而造成rce，而3.2.13这个版本通过添加黑名单已经修复了这个漏洞。

并且这题的jdk版本是17，存在模块隔离，Xstring这个类实测在hessian反序列化中无法正常触发，但是在原生反序列化中可以触发，可以参考DubheCTF的Javolution，而这里的hessian版本较高，并没有能触发toString的方法（可以参考hessianOnlyJdk）

不难想到hessian反序列化Map类型的对象时会调用put方法去恢复里面的键值对，这里可以利用hutool依赖中的JSONObject来触发getter。

JSONObject在toString时不会触发键值的getter，而是会在set/put的时候触发，并且触发的只能是已有成员变量的getter/setter，因此可以写出以下的代码

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        Bean bean = new Bean();
        Student student = new Student("test", 18);
        bean.setData("test".getBytes());
        JSONObject jsonObject = new JSONObject();
        HashMap<Object, Object> map = new HashMap<>();
        map.put("1", bean);
        map.put("2", student);
        setFieldValue(jsonObject, "raw", map);

        String ss = hSerialize(jsonObject);
//        System.out.println(ss);
        hDeserialize(ss);

bean#getObject

正常的Student类是可以触发getter的，但是我们题目中的bean却无法如预期般触发getObject，因为bean中只有data属性

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public class Bean implements Serializable {
    byte[] data;

    public Bean() {
    }

    public void setData(byte[] data) {
        this.data = data;
    }

    public Object getObject() throws Exception {
        ByteArrayInputStream byteArrayInputStream = new ByteArrayInputStream(this.data);
        BeanInputStream beanInputStream = new BeanInputStream(byteArrayInputStream);
        Object object = beanInputStream.readObject();
        return object;
    }
    ...
}

我们的思路到这里变成了可以触发任意已有属性的getter，那么我们还有可能的利用方式吗

TemplateImpl

由于此处是jdk17，在服务端上没法反序列化TemplateImpl

getConnection

容易想到的是getConnection来打jdbc，依赖有h2和hutool，但这里只能触发有属性的getter，DataSource里面也不会有connection这个属性

我们可以想到Jackson链中的POJONode

server17

jdk17+jooq，入口是裸的反序列化

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<!-- https://mvnrepository.com/artifact/org.jooq/jooq -->
<dependency>
    <groupId>org.jooq</groupId>
    <artifactId>jooq</artifactId>
    <version>3.19.3</version>
</dependency>

构建codeql数据库

从github下载jooq源码后解压，本地构建codeql数据库

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codeql database create jOOQ-qldb --overwrite -l java -s .\jOOQ-version-3.19.3\ -c "mvn install -Dmaven.test.skip=true"

或者可以使用github action来构建

给出codeql.yml，这里设置了jdk版本

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# For most projects, this workflow file will not need changing; you simply need
# to commit it to your repository.
#
# You may wish to alter this file to override the set of languages analyzed,
# or to provide custom queries or build logic.
#
# ******** NOTE ********
# We have attempted to detect the languages in your repository. Please check
# the `language` matrix defined below to confirm you have the correct set of
# supported CodeQL languages.
#
name: "CodeQL"

on:
  push:
    branches: [ "version-3.19.3" ]
  pull_request:
    branches: [ "version-3.19.3" ]
jobs:
  analyze:
    name: Analyze (${{ matrix.language }})
    # Runner size impacts CodeQL analysis time. To learn more, please see:
    #   - https://gh.io/recommended-hardware-resources-for-running-codeql
    #   - https://gh.io/supported-runners-and-hardware-resources
    #   - https://gh.io/using-larger-runners
    # Consider using larger runners for possible analysis time improvements.
    runs-on: ${{ (matrix.language == 'swift' && 'macos-latest') || 'ubuntu-latest' }}
    timeout-minutes: ${{ (matrix.language == 'swift' && 120) || 360 }}
    permissions:
      # required for all workflows
      security-events: write

      # only required for workflows in private repositories
      actions: read
      contents: read

    strategy:
      fail-fast: false
      matrix:
        include:
        - language: java-kotlin
          build-mode: autobuild
        # CodeQL supports the following values keywords for 'language': 'c-cpp', 'csharp', 'go', 'java-kotlin', 'javascript-typescript', 'python', 'ruby', 'swift'
        # Use `c-cpp` to analyze code written in C, C++ or both
        # Use 'java-kotlin' to analyze code written in Java, Kotlin or both
        # Use 'javascript-typescript' to analyze code written in JavaScript, TypeScript or both
        # To learn more about changing the languages that are analyzed or customizing the build mode for your analysis,
        # see https://docs.github.com/en/code-security/code-scanning/creating-an-advanced-setup-for-code-scanning/customizing-your-advanced-setup-for-code-scanning.
        # If you are analyzing a compiled language, you can modify the 'build-mode' for that language to customize how
        # your codebase is analyzed, see https://docs.github.com/en/code-security/code-scanning/creating-an-advanced-setup-for-code-scanning/codeql-code-scanning-for-compiled-languages
    steps:
    - name: Checkout repository
      uses: actions/checkout@v4
    - name: Setup Java JDK
      uses: actions/setup-java@v4.2.1
      with:
        java-version: '17'
        distribution: 'oracle'
          
    # Initializes the CodeQL tools for scanning.
    - name: Initialize CodeQL
      uses: github/codeql-action/init@v3
      with:
        languages: ${{ matrix.language }}
        build-mode: ${{ matrix.build-mode }}
        # If you wish to specify custom queries, you can do so here or in a config file.
        # By default, queries listed here will override any specified in a config file.
        # Prefix the list here with "+" to use these queries and those in the config file.

        # For more details on CodeQL's query packs, refer to: https://docs.github.com/en/code-security/code-scanning/automatically-scanning-your-code-for-vulnerabilities-and-errors/configuring-code-scanning#using-queries-in-ql-packs
        # queries: security-extended,security-and-quality

    # If the analyze step fails for one of the languages you are analyzing with
    # "We were unable to automatically build your code", modify the matrix above
    # to set the build mode to "manual" for that language. Then modify this step
    # to build your code.
    # ℹ️ Command-line programs to run using the OS shell.
    # 📚 See https://docs.github.com/en/actions/using-workflows/workflow-syntax-for-github-actions#jobsjob_idstepsrun
    - if: matrix.build-mode == 'manual'
      run: |
        echo 'If you are using a "manual" build mode for one or more of the' \
          'languages you are analyzing, replace this with the commands to build' \
          'your code, for example:'
        echo '  make bootstrap'
        echo '  make release'
        exit 1
    - name: Perform CodeQL Analysis
      uses: github/codeql-action/analyze@v3
      with:
        category: "/language:${{matrix.language}}"
    - name: Upload CodeQL database as artifact
      uses: actions/upload-artifact@v4
      with:
        name: codeql-database-${{ matrix.language }}
        path: /home/runner/work/_temp/codeql_databases/

Reference

https://blog.queenbridge.tech/li-yong-Github-Actions-sheng-cheng-CodeQL-shu-ju-ku----yi-AliyunCTF2024-Chain17-de-fan-xu-lie-hua-lian-wa-jue-wei-li

https://pankas.top/2024/03/28/%E9%98%BF%E9%87%8C%E4%BA%91ctf2024%E5%9D%90%E7%89%A2%E8%AE%B0%E5%BD%95/

https://xz.aliyun.com/t/14190