Expired Pointer Dereference

Opis

The product dereferences a pointer that contains a location for memory that was previously valid, but is no longer valid.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.

Inne nazwy

Dangling pointer

Skutki

• 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.

• Integrity, Confidentiality, Availability

  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.

Zapobieganie

• 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.

Przykłady podatności

• CVE-2023-26463 Chain: IPSec VPN product uses the same variable for multiple purposes in the same function (CWE-1109), leading to incorrect access control (CWE-284) and expired pointer dereference (CWE-825)
• CVE-2008-5013 access of expired memory address leads to arbitrary code execution
• CVE-2010-3257 stale pointer issue leads to denial of service and possibly other consequences
• CVE-2008-0062 Chain: a message having an unknown message type may cause a reference to uninitialized memory resulting in a null pointer dereference (CWE-476) or dangling pointer (CWE-825), possibly crashing the system or causing heap corruption.
• CVE-2007-1211 read of value at an offset into a structure after the offset is no longer valid

Słabość nadrzędna

• CWE-119 Improper Restriction of Operations within the Bounds of a Memory Buffer
• CWE-672 Operation on a Resource after Expiration or Release

Może prowadzić do

• CWE-125 Out-of-bounds Read
• CWE-787 Out-of-bounds Write

Słabości podrzędne

• CWE-415 Double Free
• CWE-416 Use After Free

Kiedy powstaje

• Implementation

Dotyczy

Memory-Unsafe, C, C++

Uwagi

There are close relationships between incorrect pointer dereferences and other weaknesses related to buffer operations. There may not be sufficient community agreement regarding these relationships. Further study is needed to determine when these relationships are chains, composites, perspective/layering, or other types of relationships. As of September 2010, most of the relationships are being captured as chains.

Many weaknesses related to pointer dereferences fall under the general term of "memory corruption" or "memory safety." As of September 2010, there is no commonly-used terminology that covers the lower-level variants.

Źródła

1. AddressSanitizer