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OpenAdvisories

Weakness (CWE)

CWE-122: Heap-based Buffer Overflow

Variant Draft

The product writes past the end of a buffer that was allocated on the heap.

How to prevent it (7 mitigations)

  1. Pre-design: Use a language or compiler that performs automatic bounds checking.

  2. Architecture and Design

    Use an abstraction library to abstract away risky APIs. Not a complete solution.

  3. Operation, Build and Compilation

    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.

  4. Operation, Build and Compilation

    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].

  5. Implementation

    Implement and perform bounds checking on input.

  6. Implementation

    Do not use dangerous functions such as gets. Look for their safe equivalent, which checks for the boundary.

  7. Operation

    Use OS-level preventative functionality. This is not a complete solution, but it provides some defense in depth.

Source: MITRE CWE-122

All Critical High Medium Low Exploited only Public exploit

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