Defectos por datos contaminados
Los defectos por datos contaminados señalan el uso de datos contaminados en determinadas operaciones. Se considera contaminado todo dato que proviene de una fuente no segura. Polyspace® considera como fuentes no seguras las siguientes:
Objetos volátiles.
Entradas externas obtenidas mediante funciones de biblioteca estándar. Las entradas externas pueden incluir:
Entradas del usuario
Variables de entorno
Contenido o ruta de archivos
Datos obtenidos de hardware
Antes de utilizar los datos, valide los datos contaminados procedentes de las citadas fuentes no seguras. Los atacantes maliciosos pueden utilizar datos contaminados no validados para atacar al programa y provocar fallos. Los defectos por datos contaminados señalan el uso de datos contaminados que no han sido validados en determinadas operaciones. Por ejemplo, Polyspace señala:
Datos contaminados en diversas operaciones numéricas.
Elementos controlados externamente, como rutas, comandos, variables de entorno e ID de host.
Datos contaminados en operaciones de memoria como la asignación o desreferenciación.
Resultados de Polyspace
Array access with tainted index | Array index from unsecure source possibly outside array bounds |
Command executed from externally controlled path | Path argument from an unsecure source |
Execution of externally controlled command | Command argument from an unsecure source vulnerable to operating system command injection |
Host change using externally controlled elements | Changing host ID from an unsecure source |
Library loaded from externally controlled path | Using a library argument from an externally controlled path |
Loop bounded with tainted value | Loop controlled by a value from an unsecure source |
Memory allocation with tainted size | Size argument to memory function is from an unsecure source |
Pointer dereference with tainted offset | Offset is from an unsecure source and dereference might be out of bounds |
Tainted division operand | Operands of division operation (/ ) come from an unsecure
source |
Tainted modulo operand | Operands of remainder operation (% ) come from an unsecure
source |
Tainted NULL or non-null-terminated string | Argument is from an unsecure source and might be NULL or not NULL-terminated |
Tainted sign change conversion | Value from an unsecure source changes sign |
Tainted size of variable length array | Size of the variable-length array (VLA) is from an unsecure source and might be zero, negative, or too large |
Tainted source used with sensitive function | Data obtained from an untrusted source is passed to user-defined sensitive function (Desde R2023b) |
Tainted string format | Input format argument is from an unsecure source |
Use of externally controlled environment variable | Value of environment variable is from an unsecure source |
Use of tainted pointer | Pointer from an unsecure source may be NULL or point to unknown memory |
Temas
- Sources of Tainting in a Polyspace Analysis
Validate tainted data obtained from external sources to avoid security risks.
- Bug Finder Defect Groups
The Bug Finder defect checkers are classified into groups such as data flow, concurrency, numerical, and so on.