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

low-risk

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.

Abstraction: Base

Common Consequences

Integrity Modify Memory
Availability Modify Memory

Detection Methods

Automated Static Analysis

This weakness can often be detected using automated static analysis tools. Many modern tools use data flow analysis or constraint-based techniques to minimize the number of false positives. Automated static analysis generally does not account for environmental considerations when reporting out-of-bounds memory operations. This can make it difficult for users to determine which warnings should be investigated first. For example, an analysis tool might report buffer overflows that originate from command line arguments in a program that is not expected to run with setuid or other special privileges.

Automated Dynamic Analysis

This weakness can be detected using dynamic tools and techniques that interact with the software using large test suites with many diverse inputs, such as fuzz testing (fuzzing), robustness testing, and fault injection. The software's operation may slow down, but it should not become unstable, crash, or generate incorrect results.

Manual Analysis

Manual analysis can be useful for finding this weakness, but it might not achieve desired code coverage within limited time constraints. This becomes difficult for weaknesses that must be considered for all inputs, since the attack surface can be too large.

Automated Dynamic Analysis

Use tools that are integrated during compilation to insert runtime error-checking mechanisms related to memory safety errors, such as AddressSanitizer (ASan) for C/C++ [REF-1518].

Automated Static Analysis - Binary or Bytecode

According to SOAR [REF-1479], the following detection techniques may be useful: Highly cost effective: Bytecode Weakness Analysis - including disassembler + source code weakness analysis Binary Weakness Analysis - including disassembler + source code weakness analysis

Manual Static Analysis - Binary or Bytecode

According to SOAR [REF-1479], the following detection techniques may be useful: Cost effective for partial coverage: Binary / Bytecode disassembler - then use manual analysis for vulnerabilities & anomalies

Dynamic Analysis with Automated Results Interpretation

According to SOAR [REF-1479], the following detection techniques may be useful: Cost effective for partial coverage: Web Application Scanner Web Services Scanner Database Scanners

Dynamic Analysis with Manual Results Interpretation

According to SOAR [REF-1479], the following detection techniques may be useful: Cost effective for partial coverage: Fuzz Tester Framework-based Fuzzer

Manual Static Analysis - Source Code

According to SOAR [REF-1479], the following detection techniques may be useful: Cost effective for partial coverage: Focused Manual Spotcheck - Focused manual analysis of source Manual Source Code Review (not inspections)

Automated Static Analysis - Source Code

According to SOAR [REF-1479], the following detection techniques may be useful: Highly cost effective: Source code Weakness Analyzer Context-configured Source Code Weakness Analyzer

Architecture or Design Review

According to SOAR [REF-1479], the following detection techniques may be useful: Highly cost effective: Formal Methods / Correct-By-Construction Cost effective for partial coverage: Inspection (IEEE 1028 standard) (can apply to requirements, design, source code, etc.)

Real-World Examples (10)

CVE CVSS EPSS KEV
CVE-2017-7269 9.8 94.4% Y
CVE-2017-7269 9.8 94.4% Y
CVE-2019-11043 8.7 94.1% Y
CVE-2007-5659 7.8 93.1% Y
CVE-2007-5659 7.8 93.1% Y
CVE-2020-15999 9.6 92.9% Y
CVE-2022-37434 9.8 92.5%
CVE-2016-6366 8.8 91.4% Y
CVE-2016-6366 8.8 91.4% Y
CVE-2016-10174 9.8 91.1% Y
6
/ 100
low-risk
Active Threat 5/50 · Minimal
Exploit Availability 1/50 · Minimal