The programmer accidentally uses the wrong operator, which changes the application logic in security-relevant ways.
These types of errors are generally the result of a typo.
Modes of Introduction:
– Implementation
Likelihood of Exploit: Low
Other: Alter Execution Logic
This weakness can cause unintended logic to be executed and other unexpected application behavior.
A software system that accepts path input in the form of internal space (‘file(SPACE)name’) without appropriate validation can lead to ambiguous path resolution and allow an attacker to traverse the file system to unintended locations or access arbitrary files.
Modes of Introduction:
– Implementation
Confidentiality, Integrity: Read Files or Directories, Modify Files or Directories
The program defines a signal handler that calls a non-reentrant function.
Modes of Introduction:
– Architecture and Design
Likelihood of Exploit: Low
Integrity, Confidentiality, Availability: Execute Unauthorized Code or Commands
It may be possible to execute arbitrary code through the use of a write-what-where condition.
Integrity: Modify Memory, Modify Application Data
Signal race conditions often result in data corruption.
Phase: Requirements
Description:
Require languages or libraries that provide reentrant functionality, or otherwise make it easier to avoid this weakness.
Phase: Architecture and Design
Description:
Design signal handlers to only set flags rather than perform complex functionality.
Phase: Implementation
Description:
Ensure that non-reentrant functions are not found in signal handlers.
Phase: Implementation
Effectiveness: Defense in Depth
Description:
Use sanity checks to reduce the timing window for exploitation of race conditions. This is only a partial solution, since many attacks might fail, but other attacks still might work within the narrower window, even accidentally.
The code does not have a default case in a switch statement, which might lead to complex logical errors and resultant weaknesses.
This flaw represents a common problem in software development, in which not all possible values for a variable are considered or handled by a given process. Because of this, further decisions are made based on poor information, and cascading failure results. This cascading failure may result in any number of security issues, and constitutes a significant failure in the system.
Modes of Introduction:
– Implementation
Integrity: Varies by Context, Alter Execution Logic
Depending on the logical circumstances involved, any consequences may result: e.g., issues of confidentiality, authentication, authorization, availability, integrity, accountability, or non-repudiation.
Phase: Implementation
Description:
Ensure that there are no unaccounted for cases, when adjusting flow or values based on the value of a given variable. In switch statements, this can be accomplished through the use of the default label.
Phase: Implementation
Description:
In the case of switch style statements, the very simple act of creating a default case can mitigate this situation, if done correctly. Often however, the default case is used simply to represent an assumed option, as opposed to working as a check for invalid input. This is poor practice and in some cases is as bad as omitting a default case entirely.
The code uses deprecated or obsolete functions, which suggests that the code has not been actively reviewed or maintained.
Modes of Introduction:
– Implementation
Other: Quality Degradation
Phase: Implementation
Description:
Refer to the documentation for the obsolete function in order to determine why it is deprecated or obsolete and to learn about alternative ways to achieve the same functionality.
Phase: Requirements
Description:
Consider seriously the security implications of using an obsolete function. Consider using alternate functions.
A NULL pointer dereference occurs when the application dereferences a pointer that it expects to be valid, but is NULL, typically causing a crash or exit.
NULL pointer dereference issues can occur through a number of flaws, including race conditions, and simple programming omissions.
Modes of Introduction:
– Implementation
Likelihood of Exploit: Medium
Availability: DoS: Crash, Exit, or Restart
NULL pointer dereferences usually result in the failure of the process unless exception handling (on some platforms) is available and implemented. Even when exception handling is being used, it can still be very difficult to return the software to a safe state of operation.
Integrity, Confidentiality, Availability: Execute Unauthorized Code or Commands, Read Memory, Modify Memory
In rare circumstances, when NULL is equivalent to the 0x0 memory address and privileged code can access it, then writing or reading memory is possible, which may lead to code execution.
Phase: Implementation
Description:
If all pointers that could have been modified are sanity-checked previous to use, nearly all NULL pointer dereferences can be prevented.
Phase: Requirements
Description:
The choice could be made to use a language that is not susceptible to these issues.
Phase: Implementation
Effectiveness: Moderate
Description:
Check the results of all functions that return a value and verify that the value is non-null before acting upon it.
Checking the return value of the function will typically be sufficient, however beware of race conditions (CWE-362) in a concurrent environment. This solution does not handle the use of improperly initialized variables (CWE-665).
Phase: Architecture and Design
Description:
Identify all variables and data stores that receive information from external sources, and apply input validation to make sure that they are only initialized to expected values.
Phase: Implementation
Description:
Explicitly initialize all your variables and other data stores, either during declaration or just before the first usage.
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.
The behavior of this function is undefined unless its control parameter is set to a specific value.
Modes of Introduction:
– Architecture and Design
Other: Quality Degradation, Varies by Context
The code uses a function that has inconsistent implementations across operating systems and versions.
Modes of Introduction:
– Architecture and Design
Other: Quality Degradation, Varies by Context
Phase: Architecture and Design, Requirements
Description:
Do not accept inconsistent behavior from the API specifications when the deviant behavior increase the risk level.
A PHP application does not properly protect against the modification of variables from external sources, such as query parameters or cookies. This can expose the application to numerous weaknesses that would not exist otherwise.
Modes of Introduction:
– Implementation
Integrity: Modify Application Data
Phase: Requirements, Implementation
Description:
Carefully identify which variables can be controlled or influenced by an external user, and consider adopting a naming convention to emphasize when externally modifiable variables are being used. An application should be reluctant to trust variables that have been initialized outside of its trust boundary. Ensure adequate checking is performed when relying on input from outside a trust boundary. Do not allow your application to run with register_globals enabled. If you implement a register_globals emulator, be extremely careful of variable extraction, dynamic evaluation, and similar issues, since weaknesses in your emulation could allow external variable modification to take place even without register_globals.
The web application does not sufficiently verify inputs that are assumed to be immutable but are actually externally controllable, such as hidden form fields.
Modes of Introduction:
– Implementation
Integrity: Modify Application Data
Without appropriate protection mechanisms, the client can easily tamper with cookies and similar web data. Reliance on the cookies without detailed validation can lead to problems such as SQL injection. If you use cookie values for security related decisions on the server side, manipulating the cookies might lead to violations of security policies such as authentication bypassing, user impersonation and privilege escalation. In addition, storing sensitive data in the cookie without appropriate protection can also lead to disclosure of sensitive user data, especially data stored in persistent cookies.
Phase: Implementation
Description:
Phase: Implementation
Description:
Inputs should be decoded and canonicalized to the application’s current internal representation before being validated (CWE-180). Make sure that the application does not decode the same input twice (CWE-174). Such errors could be used to bypass allowlist validation schemes by introducing dangerous inputs after they have been checked.