CWE-825: Expired Pointer Dereference
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The product dereferences a pointer that contains a location for memory that was previously valid, but is no longer valid.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.
- Abstraction
- BaseA weakness specific enough to point to detection and prevention methods.
- Likelihood of exploit
- Not rated by MITRE
- Status
- Incomplete
Common consequences
- Confidentiality
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.
- Availability
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.
- IntegrityConfidentialityAvailability
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.
Potential 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.
Related weaknesses
CAPEC attack patterns that exploit it
CWE 4.20 links no CAPEC attack pattern to this weakness.