CWE-825 — Expired Pointer Dereference
CWE-825: Expired Pointer Dereference
MITRE CWE weakness
| Kind | Weakness |
| Abstraction | Base |
| Status | Incomplete |
| Likelihood of exploit | — |
Description
The product dereferences a pointer that contains a location for memory that was previously valid, but is no longer valid.
When a product releases memory, but it maintains a pointer to that memory, then the memory might be re-allocated at a later time. If the original pointer is accessed to read or write data, then this could cause the product to read or modify data that is in use by a different function or process. Depending on how the newly-allocated memory is used, this could lead to a denial of service, information exposure, or code execution.
Common consequences
- Confidentiality: Read Memory
- Availability: DoS: Crash, Exit, or Restart
- Integrity, Confidentiality, Availability: Execute Unauthorized Code or Commands
Mitigations
Architecture and Design — Choose a language that provides automatic memory management.
Implementation — When freeing pointers, be sure to set them to NULL once they are freed. However, the utilization of multiple or complex data structures may lower the usefulness of this strategy.
References
- CWE page: https://cwe.mitre.org/data/definitions/825.html
- CWE list: https://cwe.mitre.org/data/index.html