CWE-183: Permissive List of Allowed Inputs

What is CWE-183?

CWE-183 is Permissive List of Allowed Inputs. The flaw arises when the product implements a protection mechanism that relies on a list of inputs (or properties of inputs) that are explicitly allowed by policy because the inputs are assumed to be safe, but the list is too permissive - that is, it allows an input that is unsafe, leading to resultant weaknesses. The database currently holds 22 vulnerabilities mapped to CWE-183 and none of them are in the CISA Known Exploited Vulnerabilities catalog.

OWASP TOP 10:2025 RANK6 — A06:2025 — Insecure Design
Related CVES (365 days)22
AbstractionBase
Likelihood of exploit-

Vulnerabilities mapped to CWE-183

22 vulnerabilities2100% increase year over year

No data

No vulnerability data in CISA KEV for CWE-183

Official definition

ByMitre CWE

The product implements a protection mechanism that relies on a list of inputs (or properties of inputs) that are explicitly allowed by policy because the inputs are assumed to be safe, but the list is too permissive - that is, it allows an input that is unsafe, leading to resultant weaknesses.

Characteristics

Alternate terms

  • Allowlist / Allow List — This is used by CWE and CAPEC instead of other commonly-used terms. Its counterpart is denylist.
  • Safelist / Safe List — This is often used by security tools such as firewalls, email or web gateways, proxies, etc.
  • Whitelist / White List — This term is frequently used, but usage has been declining as organizations have started to adopt other terms.

Modes of introduction

  • Implementation

Common consequences

ImpactScopeExplanation
Bypass Protection MechanismAccess Control-

Detection methods

MethodApproachEffectiveness
Automated Static AnalysisAutomated static analysis, commonly referred to as Static Application Security Testing (SAST), can find some instances of this weakness by analyzing source code (or binary/compiled code) without having to execute it. Typically, this is done by building a model of data flow and control flow, then searching for potentially-vulnerable patterns that connect "sources" (origins of input) with "sinks" (destinations where the data interacts with external components, a lower layer such as the OS, etc.)High

Representative vulnerabilities

Below are representative vulnerabilities related to this CWE, prioritized by severity.

Sources (2)
MITRE CWE
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