Use-After-Free

What is Use-After-Free?

Use-After-Free (UAF) is a type of memory corruption vulnerability where a program continues to use a pointer after the memory it points to has been freed. This can lead to crashes, data corruption, or arbitrary code execution.

How Use-After-Free Works

Use-After-Free typically involves the following steps:

• Memory Allocation: The program allocates memory and stores a pointer to it.
• Memory Deallocation: The program frees the memory, but the pointer is not set to null.
• Use of Freed Memory: The program continues to use the pointer, leading to undefined behavior.

Interactive Use-After-Free Example

Below is a simulation of a Use-After-Free attack. Click the button to see how an attacker exploits a Use-After-Free vulnerability.

Use-After-Free Tools and Resources

Here are some tools and resources to help you understand and defend against Use-After-Free vulnerabilities:

How to Defend Against Use-After-Free

To protect your systems from Use-After-Free vulnerabilities, follow these best practices:

• Set Pointers to Null: Always set pointers to null after freeing memory.
• Use Smart Pointers: Use smart pointers in languages like C++ to automatically manage memory.
• Enable Memory Sanitizers: Use tools like AddressSanitizer to detect Use-After-Free vulnerabilities during development.
• Conduct Code Reviews: Review code for potential Use-After-Free vulnerabilities and address them promptly.