BF Specification of CVE-2018-14557 Tenda firmware until v15.03.06.44_CN(AC7), v15.03.05.19(6318)_CN(AC9), and v15.03.06.23_CN(AC10)
-0.png)
//generated// Erroneous Code (in ‘char s;’) to Simple Declare array of chars Data Type Primitive (while it shoud have been a structure - array of chars) in Codebase (int __fastcall fromNatStaticSetting(int a1)#L5) Bare-Metal (IoT Tenda routers AC7, 9, and 10 devices) leads to Wrong Type ((char instead of array of chars))
, which propagates to Wrong Type (in ‘sprintf(&s, “nat_static.asp?page=%s”,v6);’) Sequential Reposition Stack Actual Codebase (function int __fastcall fromNatStaticSetting(int)#L16) in Bare-Metal (IoT Tenda routers AC7, 9, and 10 devices) resulting in Over Bounds Pointer
, which propagates to Over Bounds Pointer (‘sprintf(&s, “nat_static.asp?page=%s”,v6);’) Sequential Write Stack Actual Codebase (function int __fastcall fromNatStaticSetting(int a1)#L16) in Bare-Metal (IoT Tenda routers AC7, 9, and 10 devices) resulting in Buffer Overflow
. If exploited this can lead to DOS (availability loss).
int __fastcall fromNatStaticSetting(int a1)#L5
function int __fastcall fromNatStaticSetting(int)#L16
function int __fastcall fromNatStaticSetting(int a1)#L16
vendor:product: tenda:ac7_firmware:* |
|
| Class | Definition |
| DCL | Declaration (DCL) class – An object, a function, a type, or a namespace is declared or defined improperly. |
| MAD | Memory Addressing (MAD) class – The pointer to an object is initialized, repositioned, or reassigned to an improper memory address. |
| MUS | Memory Use (MUS) class – An object is initialized, read, written, or cleared improperly. |
| Operation | Definition |
| Declare | Declare operation – Specify the name and type of an object; the name, return type, and parameters of a function; or the name and type parameters of a type. |
| Reposition | Reposition operation – Change the pointer to another position inside its object. |
| Write | Write operation – Change the data value of an object to another meaningful value. |
| Cause/Consequence | Definition |
| Code Bug | Code Bug type – Defect in the implementation of the operation – 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. |
| Erroneous Code | Erroneous Code bug - There is a coding error in the implementation of the operation. |
| Type Error/Fault | Type Fault/Error type – The the set or range of allowed values is wrong or the operations allowed on them are wrong. |
| Wrong Type | Wrong Type fault/error – A data type range or structure is not correct. |
| Address Error/Fault | Address Fault/Error type – The object address in use is wrong. |
| Over Bounds Pointer | Over Bounds Pointer fault/error – Holds an address above the upper boundary of its 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. |
| Buffer Overflow | Buffer Overflow exploitable error – Writing above the upper bound of an object – aka Buffer Over-Write. |
| Operation Attribute | Definition |
| Mechanism | Mechanism operation attribute type – Shows how the buggy/faulty operation code is performed. |
| Simple | Simple operation attribute – The operation is via non-polymorphic types. |
| Sequential | Sequential operation attribute – The operation is via iterating over the object elements. |
| Source Code | Source Code operation attribute type – Shows where the operation with the bug or a faulty operand 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. |
| Execution Space | Execution Space operation attribute type – Shows where the buggy/faulty operation code is running or with what privilege level. |
| 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. |
| Operand Attribute | Definition |
| Name Kind | Name Kind operand attribute type – Shows what the entity with this name is. |
| Data Type | Data Type operand attribute – A set of allowed values and the operations allowed over them. |
| Type Kind | Type Kind operand attribute type – Shows what the data type composition is. |
| Primitive | Primitive operand attribute – A scalar data type that mimics the hardware units - e.g., int (long, short, signed), float, double, string, Boolean. A primitive data type is only language defined and is not built from other data types. |
| 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). |
| 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. |
| Address Kind | Address Kind operand attribute type - Shows what the accessed outside object's bounds memory is. |
| Moderate | Moderate operand attribute - Several bytes, but less than 1 KB, of memory. |