The program invokes a potentially dangerous function that could introduce a vulnerability if it is used incorrectly, but the function can also be used safely.
Modes of Introduction:
– Architecture and Design
Likelihood of Exploit: High
Other: Varies by Context, Quality Degradation, Unexpected State
If the function is used incorrectly, then it could result in security problems.
Phase: Build and Compilation, Implementation
Description:
Identify a list of prohibited API functions and prohibit developers from using these functions, providing safer alternatives. In some cases, automatic code analysis tools or the compiler can be instructed to spot use of prohibited functions, such as the “banned.h” include file from Microsoft’s SDL. [REF-554] [REF-7]
The product performs a calculation to determine how much memory to allocate, but an integer overflow can occur that causes less memory to be allocated than expected, leading to a buffer overflow.
Modes of Introduction:
Integrity, Availability, Confidentiality: Modify Memory, DoS: Crash, Exit, or Restart, Execute Unauthorized Code or Commands
When converting from one data type to another, such as long to integer, data can be omitted or translated in a way that produces unexpected values. If the resulting values are used in a sensitive context, then dangerous behaviors may occur.
Modes of Introduction:
– Implementation
Likelihood of Exploit: High
Other, Integrity: Unexpected State, Quality Degradation
The program could wind up using the wrong number and generate incorrect results. If the number is used to allocate resources or make a security decision, then this could introduce a vulnerability.
Phase: Implementation
Description:
Avoid making conversion between numeric types. Always check for the allowed ranges.
The software performs a calculation that generates incorrect or unintended results that are later used in security-critical decisions or resource management.
When software performs a security-critical calculation incorrectly, it might lead to incorrect resource allocations, incorrect privilege assignments, or failed comparisons among other things. Many of the direct results of an incorrect calculation can lead to even larger problems such as failed protection mechanisms or even arbitrary code execution.
Modes of Introduction:
– Architecture and Design
Likelihood of Exploit: High
Availability: DoS: Crash, Exit, or Restart
If the incorrect calculation causes the program to move into an unexpected state, it may lead to a crash or impairment of service.
Integrity, Confidentiality, Availability: DoS: Crash, Exit, or Restart, DoS: Resource Consumption (Other), Execute Unauthorized Code or Commands
If the incorrect calculation is used in the context of resource allocation, it could lead to an out-of-bounds operation (CWE-119) leading to a crash or even arbitrary code execution. Alternatively, it may result in an integer overflow (CWE-190) and / or a resource consumption problem (CWE-400).
Access Control: Gain Privileges or Assume Identity
In the context of privilege or permissions assignment, an incorrect calculation can provide an attacker with access to sensitive resources.
Access Control: Bypass Protection Mechanism
If the incorrect calculation leads to an insufficient comparison (CWE-697), it may compromise a protection mechanism such as a validation routine and allow an attacker to bypass the security-critical code.
Phase: Implementation
Description:
Understand your programming language’s underlying representation and how it interacts with numeric calculation. Pay close attention to byte size discrepancies, precision, signed/unsigned distinctions, truncation, conversion and casting between types, “not-a-number” calculations, and how your language handles numbers that are too large or too small for its underlying representation.
Phase: Implementation
Description:
Perform input validation on any numeric input by ensuring that it is within the expected range. Enforce that the input meets both the minimum and maximum requirements for the expected range.
Phase: Implementation
Description:
Use the appropriate type for the desired action. For example, in C/C++, only use unsigned types for values that could never be negative, such as height, width, or other numbers related to quantity.
Phase: Architecture and Design
Description:
Phase: Architecture and Design
Description:
Phase: Implementation
Description:
Examine compiler warnings closely and eliminate problems with potential security implications, such as signed / unsigned mismatch in memory operations, or use of uninitialized variables. Even if the weakness is rarely exploitable, a single failure may lead to the compromise of the entire system.
Phase: Testing
Description:
Use automated static analysis tools that target this type of weakness. Many modern techniques use data flow analysis to minimize the number of false positives. This is not a perfect solution, since 100% accuracy and coverage are not feasible.
Phase: Testing
Description:
Use dynamic tools and techniques that interact with the software using large test suites with many diverse inputs, such as fuzz testing (fuzzing), robustness testing, and fault injection. The software’s operation may slow down, but it should not become unstable, crash, or generate incorrect results.
The software calls a function, procedure, or routine, but the caller specifies the arguments in an incorrect order, leading to resultant weaknesses.
While this weakness might be caught by the compiler in some languages, it can occur more frequently in cases in which the called function accepts variable numbers or types of arguments, such as format strings in C. It also can occur in languages or environments that do not enforce strong typing.
Modes of Introduction:
– Implementation
Other: Quality Degradation
Phase: Implementation
Description:
Use the function, procedure, or routine as specified.
Phase: Testing
Description:
Because this function call often produces incorrect behavior it will usually be detected during testing or normal operation of the software. During testing exercise all possible control paths will typically expose this weakness except in rare cases when the incorrect function call accidentally produces the correct results or if the provided argument type is very similar to the expected argument type.
The code does not function according to its published specifications, potentially leading to incorrect usage.
When providing functionality to an external party, it is important that the software behaves in accordance with the details specified. When requirements of nuances are not documented, the functionality may produce unintended behaviors for the caller, possibly leading to an exploitable state.
Modes of Introduction:
– Implementation
Other: Quality Degradation
Phase: Implementation
Description:
Ensure that your code strictly conforms to specifications.
The software calls a function, procedure, or routine, but the caller specifies too many arguments, or too few arguments, which may lead to undefined behavior and resultant weaknesses.
Modes of Introduction:
– Implementation
Other: Quality Degradation
Phase: Testing
Description:
Because this function call often produces incorrect behavior it will usually be detected during testing or normal operation of the software. During testing exercise all possible control paths will typically expose this weakness except in rare cases when the incorrect function call accidentally produces the correct results or if the provided argument type is very similar to the expected argument type.
The software calls a function, procedure, or routine, but the caller specifies an argument that is the wrong data type, which may lead to resultant weaknesses.
This weakness is most likely to occur in loosely typed languages, or in strongly typed languages in which the types of variable arguments cannot be enforced at compilation time, or where there is implicit casting.
Modes of Introduction:
– Implementation
Other: Quality Degradation
Phase: Testing
Description:
Because this function call often produces incorrect behavior it will usually be detected during testing or normal operation of the software. During testing exercise all possible control paths will typically expose this weakness except in rare cases when the incorrect function call accidentally produces the correct results or if the provided argument type is very similar to the expected argument type.
The software calls a function, procedure, or routine, but the caller specifies an argument that contains the wrong value, which may lead to resultant weaknesses.
Modes of Introduction:
– Implementation
Other: Quality Degradation