CWE-121: Stack-based Buffer Overflow
Description
A stack-based buffer overflow condition is a condition where the buffer being overwritten is allocated on the stack (i.e., is a local variable or, rarely, a parameter to a function).
- Abstraction
- VariantA weakness tied to a specific language, technology or resource.
- Likelihood of exploit
- High
- Status
- Draft
Common consequences
- Availability
Modify Memory; DoS: Crash, Exit, or Restart; DoS: Resource Consumption (CPU); DoS: Resource Consumption (Memory)
Buffer overflows generally lead to crashes. Other attacks leading to lack of availability are possible, including putting the program into an infinite loop.
- IntegrityConfidentialityAvailabilityAccess Control
Modify Memory; Execute Unauthorized Code or Commands; Bypass Protection Mechanism
Buffer overflows often can be used to execute arbitrary code, which is usually outside the scope of a program's implicit security policy.
- IntegrityConfidentialityAvailabilityAccess ControlOther
Modify Memory; Execute Unauthorized Code or Commands; Bypass Protection Mechanism; Other
When the consequence is arbitrary code execution, this can often be used to subvert any other security service.
Potential mitigations
- OperationBuild and CompilationEnvironment HardeningEffectiveness: Defense in Depth
Use automatic buffer overflow detection mechanisms that are offered by certain compilers or compiler extensions. Examples include: the Microsoft Visual Studio /GS flag, Fedora/Red Hat FORTIFY_SOURCE GCC flag, StackGuard, and ProPolice, which provide various mechanisms including canary-based detection and range/index checking. D3-SFCV (Stack Frame Canary Validation) from D3FEND discusses canary-based detection in detail.
- Architecture and Design
Use an abstraction library to abstract away risky APIs. Not a complete solution.
- Implementation
Implement and perform bounds checking on input.
- Implementation
Do not use dangerous functions such as gets. Use safer, equivalent functions which check for boundary errors.
- OperationBuild and CompilationEnvironment HardeningEffectiveness: Defense in Depth
Run or compile the software using features or extensions that randomly arrange the positions of a program's executable and libraries in memory. Because this makes the addresses unpredictable, it can prevent an attacker from reliably jumping to exploitable code. Examples include Address Space Layout Randomization (ASLR) and Position-Independent Executables (PIE). Imported modules may be similarly realigned if their default memory addresses conflict with other modules, in a process known as rebasing (for Windows) and prelinking (for Linux) using randomly generated addresses. ASLR for libraries...
Related weaknesses
CAPEC attack patterns that exploit it
CWE 4.20 links no CAPEC attack pattern to this weakness.