| Operations | Definition |
| Initialize Object | Initialize Object operation – Change the undefined data value of an object to a meaningful one – e.g., after an object is allocated. |
| Dereference | Dereference operation – Access object for reading or for writing, which are relevant to the operations Initialize Object, Read, Write, and Clear. |
| Read | Read operation – Use the value of an object's data. |
| Write | Write operation – Change the data value of an object to another meaningful value. |
| Clear | Clear operation – Change the meaningful value of an object to a non-meaningful one (e.g. via zeroization) – e.g. before object deallocation. |
| Operands | Definition |
| Data | Data operand – The data value of an object – stored in object's memory. |
| Type | Type operand – 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 | Address operand attribute – The memory address for an object. It is data of another object, the object's pointer, used to reference and traverse the object. |
| Size | Size operand – 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 Bug | Code Bug Type – A code operation defect – proper operands over an improper operation. A first cause for the chain of weaknesses underlying a software security vulnerability. Must be fixed to resolve the vulnerability. |
| Missing Code | |
| Erroneous Code | |
| Data Fault | Data Fault/Error Type – The object data has harmed semantics or inconsistent or wrong value |
| Forbidden Address | Forbidden Address fault/error – The pointer holds an OS protected address (includs the zero address -- a NULL pointer) or non-existing address. |
| Wrong Size | Wrong Size fault/error – The value used as size does not match the actual size of the object (e.g., to restrict pointer repositioning or index increment/decrement in a repetition statement). |
| Type Fault | Type Fault/Error Type – The the set or range of allowed values is wrong or the operations allowed on them are wrong. |
| Casted Pointer | Casted Pointer fault/error – The pointer does not match the type of the object due to wrong type casting. |
| Address Fault | Address Fault/Error Type – The object address in use is wrong. |
| NULL Pointer | |
| Wild Pointer | Wild Pointer fault/error – Holds an arbitrary address, because it has not been initialized or an erroneous allocation routine is used. |
| Dangling Pointer | Dangling Pointer fault/error – Still holds the address of its successfully deallocated object (e.g., pointer to a freed heap object or with a returned by a function stack object address). |
| Untrusted Pointer | Untrusted Pointer fault/error – The pointer is modified to an improperly checked address. |
| Over Bounds Pointer | Over Bounds Pointer fault/error – Holds an address above the upper boundary of its object. |
| Under Bounds Pointer | Under Bounds Pointer fault/error – Holds an address below the lower boundary of its object. |
| Wrong Position Pointer | Wrong Position Pointer fault/error – Holds the address of a miscalculated position inside its object bounds. |
| Size Fault | Size Fault/Error Type – The object size in use is wrong. |
| Not Enough Memory | Not Enough Memory fault/error – The allocated memory is too little for the data it should store. |
| Consequences | Definition |
| Data Error | Data Fault/Error Type – The object data has harmed semantics or inconsistent or wrong value |
| Uninitialized Object | |
| Memory Corruption/Disclosure Final Error | Memory Corruption/Disclosure exploitable error type – An exploitable or undefined system behavior caused by memory addressing, allocation, use, and deallocation bugs. |
| Not Cleared Object | Not Cleared Object exploitable error – An object's data value is not changed to a non-meaningful one before deallocation. |
| NULL Pointer Dereference | NULL Pointer Dereference exploitable error – An attempt to access an object for reading or writing via a NULL pointer. |
| Untrusted Pointer Dereference | Untrusted Pointer Dereference exploitable error – An attempt to access an object via an altered pointer (not legitimate dereference of a tainted pointer). |
| Object Corruption | Object Corruption exploitable error – An object's data value is unintentionally altered. |
| Type Confusion | Type Confusion exploitable error – An object and its pointer have different types. |
| Use After Deallocate | Use After Deallocate (Use After Free/Return) exploitable error – An attempt to use (dereference, read, write, or clear) a deallocated object (e.g., a freed heap object -- Use After Free) or out of scope object (e.g., returned by a function address of a stack object -- Use After Return). |
| Buffer Overflow | Buffer Overflow exploitable error – Writing above the upper bound of an object – aka Buffer Over-Write. |
| Buffer Underflow | Buffer Underflow exploitable error – Writing below the lower bound of an object – aka Buffer Under-Write. |
| Buffer Over-Read | Buffer Over-Read exploitable error – Reading above the upper bound of an object. |
| Buffer Under-Read | Buffer Under-Read exploitable error – Reading below the lower bound of an object. |
| Uninitialized Pointer Dereference | Uninitialized Pointer Dereference exploitable error – An attempt to access an object for reading or writing via an uninitialized pointer. |
| Operations Attributes | Definition |
| Mechanism | Mechanism operation attribute type – Shows how the buggy/faulty operation code is performed. |
| Direct | Direct operation attribute – The operation is performed on a particular object element. |
| Sequential | Sequential operation attribute – The operation is performed after iterating over the object elements. |
| Source Code | Source Code operation attribute type – Shows where the buggy/faulty operation code is in the program – in what kind of software. |
| Codebase | Codebase operation attribute – The operation is in the programmer's code - in the application itself. |
| Third-Party | Third-Party operation attribute – The operation is in a third-party software. |
| Standard Library | Standard Library operation attribute – The operation is in the standard library for a particular programming language. |
| Compiler/Interpreter | Compiler/Interpreter operation attribute – The operation is in the language processor that allows execution or creates executables (compiler, assembler, interpreter). |
| Execution Space | Execution Space operation attribute type – Shows where the buggy/faulty operation code is running or with what privilege level. |
| Userland | Userland operation attribute – The bugged code runs in an environment with privilege levels, but in unprivileged mode (e.g., ring 3 in x86 architecture). |
| Kernel | Kernel operation attribute – The bugged code runs in an environment with privilege levels with access privileged instructions (e.g., ring 0 in x86 architecture). |
| Bare-Metal | Bare-Metal operation attribute – 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 Kind | Address Kind operand attribute type - Shows what the accessed outside object's bounds memory is. |
| Huge | Huge operand attribute - More than 1 KB of memory. |
| Moderate | Moderate operand attribute - Several bytes, but less than 1 KB, of memory. |
| Little | Little operand attribute - A few bytes of memory. |
| Address State | Address State operand attribute type - State operand attribute type – Shows where the address is in the memory layout. |
| Stack | Stack operand attribute – The object is a non-static local variable (defined in a function, a passed parameter, or a function return address). |
| Heap | Heap operand attribute – The object is a dynamically allocated data structure (e.g., via malloc() and new). |
| /other/ | /other/ – Other kinds of memory layout (e.g. Uninitialized Data Segment, Data Segment, and Code Segment could be used for C). |
| Size Kind | Size Kind operand attribute type – Shows what the limit for traversal of the object is. |
| Actual | Actual operand attribute – The real size of an object. |
| Used | Used operand attribute – A supplied size for an object. |
