The program accesses or uses a pointer that has not been initialized.
Extended Description
If the pointer contains an uninitialized value, then the value might not point to a valid memory location. This could cause the program to read from or write to unexpected memory locations, leading to a denial of service. If the uninitialized pointer is used as a function call, then arbitrary functions could be invoked. If an attacker can influence the portion of uninitialized memory that is contained in the pointer, this weakness could be leveraged to execute code or perform other attacks.
Depending on memory layout, associated memory management behaviors, and program operation, the attacker might be able to influence the contents of the uninitialized pointer, thus gaining more fine-grained control of the memory location to be accessed.
Terminology Notes
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.
Common Consequences
Scope
Effect
Confidentiality
Technical Impact: Read memory
If the uninitialized pointer is used in a read operation, an attacker
might be able to read sensitive portions of memory.
Availability
Technical Impact: DoS: crash / exit /
restart
If the uninitialized pointer references a memory location that is not
accessible to the program, 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
Technical Impact: Execute unauthorized code or
commands
If the uninitialized pointer is used in a function call, or points to
unexpected data in a write operation, then code execution may be
possible.
Step-based manipulation: invocation of debugging
function before the primary initialization function leads to access of an
uninitialized pointer and code execution.
Under-studied and probably under-reported as of September 2010. This
weakness has been reported in high-visibility software, but applied
vulnerability researchers have only been investigating it since
approximately 2008, and there are only a few public reports. Few reports
identify weaknesses at such a low level, which makes it more difficult to
find and study real-world code examples.
References
[REF-7] Mark Dowd, John McDonald
and Justin Schuh. "The Art of Software Security Assessment". Chapter 7, "Variable Initialization", Page
312.. 1st Edition. Addison Wesley. 2006.
Maintenance Notes
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.
Content History
Submissions
Submission Date
Submitter
Organization
Source
2010-09-22
MITRE
Internal CWE Team
Modifications
Modification Date
Modifier
Organization
Source
2012-05-11
CWE Content Team
MITRE
Internal
updated References
2015-12-07
CWE Content Team
MITRE
Internal
updated Relationships
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May 05, 2017
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