George0Papasotiriou/CVE-2026-9997-VPN-Split-Tunneling-Bypass-via-DHCP-Option-Injection
GitHub: George0Papasotiriou/CVE-2026-9997-VPN-Split-Tunneling-Bypass-via-DHCP-Option-Injection
一个模拟通过注入 DHCP Option 121 静态路由绕过 VPN 分隧策略的概念验证工具,用于复现 CVE-2026-9997 漏洞。
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## CVE-2026-9997 – 通过注入 DHCP 选项绕过 VPN Split‑Tunneling
### **程序代码(Python 模拟 DHCP 服务器 + 客户端)**
```
#!/usr/bin/env python3
# rogue_dhcp_server.py - 注入静态路由以绕过 VPN split tunnel
import socket, struct, threading
def send_dhcp_offer(client_mac, offer_ip):
# Craft a DHCP OFFER packet with Option 121 (Classless Static Route)
# This option adds a route that sends traffic to a sensitive subnet via the attacker's gateway.
# We'll simulate by creating a raw packet (simplified).
# In a real attack, we'd use scapy; here we just demonstrate the concept.
print(f"Sending DHCP OFFER to {client_mac} with malicious static route...")
# The client would then apply this route and leak traffic.
```
# CVE-2026-9997 – 通过注入 DHCP 选项绕过 VPN Split‑Tunneling

## 概述
企业 VPN 客户端在未经校验的情况下接受本地网络的 DHCP 选项(Option 121 – Classless Static Routes)。同一局域网内的攻击者可以注入路由,将敏感流量发送到加密的 VPN 隧道之外。
## 漏洞详情
- **类型:** 网络配置注入
- **影响:** 数据泄露,绕过 VPN 安全策略。
- **根本原因:** VPN 客户端即使在隧道建立之后,也会盲目应用由 DHCP 提供的静态路由。
## 漏洞利用演示
1. 启动恶意 DHCP 服务器:
python rogue_dhcp_server.py
2. 在受害机器(模拟)上,运行客户端模拟:
python vpn_client_sim.py
标签:DHCP, Python, VPN, 无后门, 网络安全, 逆向工具, 隐私保护