Common Weakness Enumeration

    CWE Definition / CWE-120

    CWE-120: Buffer Copy without Checking Size of Input ('Classic Buffer Overflow')

    The product copies an input buffer to an output buffer without verifying that the size of the input buffer is less than the size of the output buffer.

    Published:19 Jul 2006
    Organization:MITRE
    Modified:21 Jan 2026

    Related Weakness

    CWE-787: Out-of-bounds Write

    CWE-119: Improper Restriction of Operations within the Bounds of a Memory Buffer

    CWE-787: Out-of-bounds Write

    CWE-787: Out-of-bounds Write

    CWE-123: Write-what-where Condition

    CWE-20: Improper Input Validation