Expired Pointer Dereference
This vulnerability occurs when a program tries to use a pointer that still points to a memory location that has already been freed or released.
This issue, often called a 'use-after-free' scenario, happens when your code frees a block of memory but accidentally keeps a reference (pointer) to it. Later, when that same pointer is used to read or write data, the memory may have been reallocated for a completely different purpose within your application or system. This means you're now interacting with data you didn't intend to, leading to unpredictable behavior. The consequences depend entirely on what now occupies that memory region. You might crash the program (denial of service), read sensitive information that belongs elsewhere (information exposure), or, in the worst case, have attacker-controlled data executed as code. This makes expired pointer dereference a critical weakness that can serve as a gateway to severe security breaches.
Impact: Read Memory
If the expired pointer is used in a read operation, an attacker might be able to control data read in by the application.
Impact: DoS: Crash, Exit, or Restart
If the expired pointer references a memory location that is not accessible to the product, or points to a location that is "malformed" (such as NULL) or larger than expected by a read or write operation, then a crash may occur.
Impact: Execute Unauthorized Code or Commands
If the expired pointer is used in a function call, or points to unexpected data in a write operation, then code execution may be possible.
ID : DX-71
The following code shows a simple example of a use after free error:Code Example:
cID : DX-72
The following code shows a simple example of a double free error:Code Example:
cDangling pointer
- Memory Management
- Memory