CWE-74: Failure to Sanitize Data into a Different Plane ('Injection')
Failure to Sanitize Data into a Different Plane ('Injection')
Weakness ID: 74 (Weakness Class)
Status: Incomplete
Description
Description Summary
The software fails to adequately filter user-controlled input
data for syntax that has control-plane implications.
Extended Description
Software has certain assumptions about what constitutes data and control
respectively. It is the lack of verification of these assumptions for
user-controlled input that leads to injection problems. Injection problems
encompass a wide variety of issues -- all mitigated in very different ways
and usually attempted in order to alter the control flow of the process. For
this reason, the most effective way to discuss these weaknesses is to note
the distinct features which classify them as injection weaknesses. The most
important issue to note is that all injection problems share one thing in
common -- i.e., they allow for the injection of control plane data into the
user-controlled data plane. This means that the execution of the process may
be altered by sending code in through legitimate data channels, using no
other mechanism. While buffer overflows, and many other flaws, involve the
use of some further issue to gain execution, injection problems need only
for the data to be parsed. The most classic instantiations of this category
of weakness are SQL injection and format string vulnerabilities.
Time of Introduction
Architecture and Design
Implementation
Applicable Platforms
Languages
All
Common Consequences
Scope
Effect
Confidentiality
Many injection attacks involve the disclosure of important information
-- in terms of both data sensitivity and usefulness in further
exploitation
Authentication
In some cases injectable code controls authentication; this may lead
to remote vulnerability
Access Control
Injection attacks are characterized by the ability to significantly
change the flow of a given process, and in some cases, to the execution
of arbitrary code.
Integrity
Data injection attacks lead to loss of data integrity in nearly all
cases as the control-plane data injected is always incidental to data
recall or writing.
Accountability
Often the actions performed by injected control code are
unlogged.
Likelihood of Exploit
Very High
Potential Mitigations
Phase
Description
Requirements specification: Programming languages and supporting
technologies might be chosen which are not subject to these
issues.
Implementation
Utilize an appropriate mix of white-list and black-list parsing to
filter control-plane syntax from all input.
Weakness Ordinalities
Ordinality
Description
Primary
(where the
weakness exists independent of other weaknesses)
In the development view (CWE-699), this is classified as an Input
Validation problem (CWE-20) because many people do not distinguish between
the consequence/attack (injection) and the protection mechanism that
prevents the attack from succeeding. In the research view (CWE-1000),
however, input validation is only one potential protection mechanism (output
encoding is another), and there is a chaining relationship between improper
input validation and the failure to enforce the structure of messsages to
other components. Other issues not directly related to input validation,
such as race conditions, could similarly impact message structure.
Description
