| Operations | Definition |
| Initialize Object | Change the undefined data value of an object to a meaningful one -- e.g., after an object is allocated. |
| Dereference | Access object for reading or for writing. It is relevant to the operations Initialize Object, Read, Write, and Clear. |
| Read | Use the value of an object data. |
| Write | Change the data value of an object to another meaningful value. |
| Clear | Change the meaningful value of an object to a non-meaningful one (e.g. via zeroization) -- e.g. before object's deallocated. |
| Operands | Definition |
| Data | The data value of an object -- stored in object's memory. |
| Type | The data type of an object -- the set of allowed values (e.g., char is within [-128, 127]) and the operations allowed over them (e.g., +, *, mod). |
| Address | The memory address for an object. Its value is data of another object, the object's pointer, used to reference and traverce the object. |
| Size | The memory size of an object -- the number of bytes allocated for an object in memory. Its value is contained by (is data of) of another object. |
| Causes | Definition |
| Code Defect Bug | The operation has a bug, which is the first cause for the chain of weaknesses underlying a software security vulnerability. The bug must be fixed to resolve the vulnerability. |
| Missing Code | The entire operation implementation or a part of its specification is absent. |
| Mismatched Operation | The deallocation function does not match the allocation function used for the same object. |
| Erroneous Code | The operation implementation has a bug. |
| Data Fault | The object data has harmed semantics or inconsistent or wrong value |
| Forbidden Address | The pointer points to an OS protected or non-existing address. |
| Wrong Size | The value used as size does not match the actual size of the object. |
| Type Fault | The set or range of allowed values is wrong or the operations allowed on them are wrong. |
| Casted Pointer | The pointer does not match the type of the object due to wrong type casting. |
| Address Fault | The object address in use is wrong. |
| NULL Pointer | Points to the zero address, a specific invalid address. |
| Wild Pointer | Points to an arbitrary address, because it has not been initialized or an erroneous allocation routine is used. |
| Dangling Pointer | Still points to the address of its successfully deallocated object. |
| Untrusted Pointer | The pointer is modified to an improperly checked address. |
| Over Bounds Pointer | Points above the upper boundary of its object. |
| Under Bounds Pointer | Points below the lower boundary of its object. |
| Wrong Position Pointer | Points to a miscalculated position inside its object bounds. |
| Size Fault | The object size in use is wrong. |
| Not Enough Memory | The allocated memory is too little for the data it should store. |
| Consequences | Definition |
| Data Error | The object data has harmed semantics or inconsistent or wrong value |
| Uninitialized Object | |
| Memory Corruption/Disclosure Final Error | An exploitable or undefined system behavior caused by memory addressing, allocation, use, and deallocation bugs. |
| Not Cleared Object | An object's data value is not changed to a non-meaningful one before deallocation. |
| NULL Pointer Dereference | An attempt to access an object for reading or writing via a NULL pointer. |
| Untrusted Pointer Dereference | An attempt to access an object via an altered pointer (not legitimate dereference of a tainted pointer). |
| Object Corruption | An object's data value is unintentionally altered. |
| Type Confusion | An object and its pointer have different types. |
| Use After Free | An attempt to use (dereference, read, write, or clear) a deallocated object. |
| Buffer Overflow | Writes above the upper bound of an object -- aka Buffer Over-Write. |
| Buffer Underflow | Writes below the lower bound of an object -- aka Buffer Under-Write. |
| Buffer Over-Read | Reads above the upper bound of an object. |
| Buffer Under-Read | Reads below the lower bound of an object. |
| Uninitialized Pointer Dereference | An attempt to access an object for reading or writing via an uninitialized pointer. |
| Operations Attributes | Definition |
| Mechanism | Shows how the buggy/faulty operation code is performed. |
| Direct | The operation is performed on a particular object element. |
| Sequential | The operation is performed after iterating over the object elements. |
| Source Code | Shows where the buggy/faulty operation code is in the program -- in what kind of software. |
| Codebase | The operation is in the programmer's code - in the application itself. |
| Third-Party | The operation is in a third-party software. |
| Standard Library | The operation is in the standard library for a particular programming language. |
| Compiler/Interpreter | The operation is in the language processor that allows execution or creates executables (compiler, assembler, interpreter). |
| Execution Space | Shows where the buggy/faulty operation code is running or with what privilege level). |
| Userland | The bugged code runs in an environment with privilege levels, but in unprivileged mode (e.g., ring 3 in x86 architecture). |
| Kernel | The bugged code runs in an environment with privilege levels with access privileged instructions (e.g., ring 0 in x86 architecture). |
| Bare-Metal | The bugged code runs in an environment without privilege control. Usually, the program is the only software running and has total access to the hardware. |
| Operands Attributes | Definition |
| Address State | Shows where the address is in the memory layout. |
| Stack | The object is a non-static local variable (defined in a function, a passed parameter, or a function return address). |
| Heap | The object is a dynamically allocated data structure (e.g., via malloc() and new). |
| /other/ | Other kinds of memory layout (e.g. Uninitialized Data Segment, Data Segment, and Code Segment could be used for C). |
| Size Kind | Shows what the limit for traversal of the object is. |
| Actual | The real size of an object. |
| Used | A supplied size for an object. |
