CWE-416 — Use After Free
CWE-416: Use After Free
MITRE CWE weakness
| Kind | Weakness |
| Abstraction | Variant |
| Status | Stable |
| Likelihood of exploit | High |
Description
The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.
Common consequences
- Integrity: Modify Memory
- Availability: DoS: Crash, Exit, or Restart
- Confidentiality: Read Memory
- 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/416.html
- CWE list: https://cwe.mitre.org/data/index.html