George0Papasotiriou/CVE-2026-7777-Rust-Use-After-Free-in-Unsafe-Web-Server
GitHub: George0Papasotiriou/CVE-2026-7777-Rust-Use-After-Free-in-Unsafe-Web-Server
一个 Rust 多线程 Web 服务器的教学示例，用于演示 unsafe 代码中因竞态条件引发的 use-after-free 漏洞原理。
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## CVE-2026-7777 – Rust Unsafe Web Server 中的 Use-After-Free
### **程序代码 (Rust)**
```
// uaf_server.rs - Vulnerable Rust HTTP server with use-after-free
use std::sync::{Arc, Mutex};
use std::thread;
use std::io::prelude::*;
use std::net::{TcpListener, TcpStream};
struct SharedBuffer {
data: Vec,
}
impl SharedBuffer {
fn new() -> Self { SharedBuffer { data: vec![0; 1024] } }
}
fn handle_client(mut stream: TcpStream, buffer: Arc>) {
// Simulate reading request and writing response.
let mut buf = [0; 512];
stream.read(&mut buf).unwrap();
let b = buffer.lock().unwrap();
let ptr = b.data.as_ptr() as *mut u8; // raw pointer
// Drop the lock early? In unsafe block we might send the pointer to another thread.
// Here we simulate a bug: the SharedBuffer is dropped, but we later use the pointer.
drop(b);
// After lock is released, another thread could replace the Vec, freeing the old allocation.
// Unsafe write through the dangling pointer.
unsafe {
*ptr = 42; // use after free!
}
stream.write(b"HTTP/1.1 200 OK\r\n\r\nHello").unwrap();
}
fn main() {
let listener = TcpListener::bind("127.0.0.1:7878").unwrap();
let buffer = Arc::new(Mutex::new(SharedBuffer::new()));
for stream in listener.incoming() {
let stream = stream.unwrap();
let buf_clone = Arc::clone(&buffer);
thread::spawn(move || {
handle_client(stream, buf_clone);
});
}
}
```
# CVE-2026-7777 – Rust Web Server 中 Unsafe 的 Use-After-Free
## 概述
一个 Rust web server 使用 unsafe 代码跨线程共享 buffer。竞态条件导致了 use-after-free，可能会引起内存损坏或信息泄露。
## 漏洞详情
- **类型：** Use-After-Free (内存安全)
- **影响：** 拒绝服务，可能导致任意代码执行。
- **根本原因：** 在锁的保护下从 `Vec` 获取了 raw pointer，随后锁被 drop，并且该 vector 被另一个线程替换，从而在指针仍在使用时释放了内存。
## 漏洞利用演示
1. 编译并运行存在漏洞的 server：
rustc uaf_server.rs
./uaf_server
2. 运行多线程触发器：
python trigger_uaf.py
标签：Rust, Web服务器, 内存安全, 可视化界面, 漏洞验证代码, 网络流量审计, 逆向工具, 通知系统, 配置错误, 释放后重用