Buffer Overflow

ID

buffer_overflow

Severity

high

Kind

Buffer Overflow

CWE

120

Description

Buffer overflow errors are characterized by the overwriting of memory spaces of the background web process, which should have never been modified intentionally or unintentionally. Overwriting values of the IP (Instruction Pointer), BP (Base Pointer) and other registers causes exceptions, segmentation faults, and other process errors to occur. Usually, these errors end execution of the application in an unexpected way.

Rationale

Buffer overflow vulnerabilities enable attackers to overwrite critical memory locations by providing input exceeding allocated buffer sizes. Successful exploitation allows arbitrary code execution by overwriting return addresses, function pointers, or instruction registers to redirect program flow to attacker-controlled code. Attackers can achieve complete system compromise, privilege escalation, or denial of service.

The vulnerability typically affects native code components, web server modules, or backend processes written in memory-unsafe languages like C or C++ that fail to validate input length before copying to fixed-size buffers.

Remediation

  • Implement strict input length validation before copying data into fixed-size buffers.

  • Recompile affected executables with proper length checking and modern security hardening options enabled. Enable compiler protections such as stack canaries, address space layout randomization (ASLR), and data execution prevention (DEP).

  • Use safe string handling functions that enforce buffer boundaries, such as strncpy, snprintf, or strlcpy instead of unsafe functions like strcpy or sprintf.

  • Consider migrating critical components to memory-safe languages.

And last but not least:

  • Validate and sanitize all input from untrusted sources, preferring white-listing and accept-only-good-known strategies.

References