CWE-121 — Stack-based Buffer Overflow
CWE-121: Stack-based Buffer Overflow
MITRE CWE weakness
| Kind | Weakness |
| Abstraction | Variant |
| Status | Draft |
| Likelihood of exploit | High |
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).
Common consequences
- Availability: Modify Memory, DoS: Crash, Exit, or Restart, DoS: Resource Consumption (CPU), DoS: Resource Consumption (Memory)
- Integrity, Confidentiality, Availability, Access Control: Modify Memory, Execute Unauthorized Code or Commands, Bypass Protection Mechanism
- Integrity, Confidentiality, Availability, Access Control, Other: Modify Memory, Execute Unauthorized Code or Commands, Bypass Protection Mechanism, Other
Mitigations
Operation — 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 [REF-1334] 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.
Operation — 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) [REF-58] [REF-60] and Position-Independent Executables (PIE) [REF-64]. 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) [REF-1332] using randomly generated addresses. ASLR for libraries cannot be used in conjunction with prelink since it would require relocating the libraries at run-time, defeating the whole purpose of prelinking. For more information on these techniques see D3-SAOR (Segment Address Offset Randomization) from D3FEND [REF-1335].
References
- CWE page: https://cwe.mitre.org/data/definitions/121.html
- CWE list: https://cwe.mitre.org/data/index.html