Improper Update of Reference Count

Opis

The product uses a reference count to manage a resource, but it does not update or incorrectly updates the reference count.

Reference counts can be used when tracking how many objects contain a reference to a particular resource, such as in memory management or garbage collection. When the reference count reaches zero, the resource can be de-allocated or reused because there are no more objects that use it. If the reference count accidentally reaches zero, then the resource might be released too soon, even though it is still in use. If all objects no longer use the resource, but the reference count is not zero, then the resource might not ever be released.

Skutki

• Availability

  DoS: Resource Consumption (Memory); DoS: Resource Consumption (Other)

  An adversary that can cause a resource counter to become inaccurate may be able to create situations where resources are not accounted for and not released, thus causing resources to become scarce for future needs.

• Availability

  DoS: Crash, Exit, or Restart

  An adversary that can cause a resource counter to become inaccurate may be able to force an error that causes the product to crash or exit out of its current operation.

Przykłady podatności

• CVE-2002-0574 chain: reference count is not decremented, leading to memory leak in OS by sending ICMP packets.
• CVE-2004-0114 Reference count for shared memory not decremented when a function fails, potentially allowing unprivileged users to read kernel memory.
• CVE-2006-3741 chain: improper reference count tracking leads to file descriptor consumption
• CVE-2007-1383 chain: integer overflow in reference counter causes the same variable to be destroyed twice.
• CVE-2007-1700 Incorrect reference count calculation leads to improper object destruction and code execution.
• CVE-2008-2136 chain: incorrect update of reference count leads to memory leak.
• CVE-2008-2785 chain/composite: use of incorrect data type for a reference counter allows an overflow of the counter, leading to a free of memory that is still in use.
• CVE-2008-5410 Improper reference counting leads to failure of cryptographic operations.
• CVE-2009-1709 chain: improper reference counting in a garbage collection routine leads to use-after-free
• CVE-2009-3553 chain: reference count not correctly maintained when client disconnects during a large operation, leading to a use-after-free.
• CVE-2009-3624 Reference count not always incremented, leading to crash or code execution.
• CVE-2010-0176 improper reference counting leads to expired pointer dereference.
• CVE-2010-0623 OS kernel increments reference count twice but only decrements once, leading to resource consumption and crash.
• CVE-2010-2549 OS kernel driver allows code execution
• CVE-2010-4593 improper reference counting leads to exhaustion of IP addresses
• CVE-2011-0695 Race condition causes reference counter to be decremented prematurely, leading to the destruction of still-active object and an invalid pointer dereference.
• CVE-2012-4787 improper reference counting leads to use-after-free

Słabość nadrzędna

• CWE-664 Improper Control of a Resource Through its Lifetime

Może prowadzić do

• CWE-672 Operation on a Resource after Expiration or Release
• CWE-772 Missing Release of Resource after Effective Lifetime

Kiedy powstaje

• Implementation

Dotyczy

C, C++, Not Language-Specific

Źródła

1. Windows Kernel Reference Count Vulnerabilities - Case Study — Mateusz "j00ru" Jurczyk, 2012