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CWE-122

ヒープベースのバッファオーバーフロー

Heap-based Buffer Overflow
脆弱性 レビュー中
JA

ヒープ・オーバーフロー状態とは、上書き可能なバッファがメモリのヒープ部分に確保されるバッファ・オーバーフローのことで、一般的にはmalloc()などのルーチンを使ってバッファが確保されたことを意味する。

EN

A heap overflow condition is a buffer overflow, where the buffer that can be overwritten is allocated in the heap portion of memory, generally meaning that the buffer was allocated using a routine such as malloc().

Scope: Availability / Impact: DoS: Crash, Exit, or Restart; DoS: Resource Consumption (CPU); DoS: Resource Consumption (Memory)
Scope: Integrity, Confidentiality, Availability, Access Control / Impact: Execute Unauthorized Code or Commands; Bypass Protection Mechanism; Modify Memory
Scope: Integrity, Confidentiality, Availability, Access Control, Other / Impact: Execute Unauthorized Code or Commands; Bypass Protection Mechanism; Other
Pre-design: Use a language or compiler that performs automatic bounds checking.
Use an abstraction library to abstract away risky APIs. Not a complete solution.
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.
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].
Implement and perform bounds checking on input.
Do not use dangerous functions such as gets. Look for their safe equivalent, which checks for the boundary.
Use OS-level preventative functionality. This is not a complete solution, but it provides some defense in depth.
MITRE公式ページ — CWE-122