CWE-20

What is CWE-20 (Improper Input Validation)?

The product receives input but does not validate or incorrectly validates that the input has the properties required to process the data safely.

Vulnerability Insights

Improper Input Validation (CWE-20) represents a significant security risk across modern software systems. This weakness enables attackers to exploit software security flaws in applications, potentially leading to unauthorized access, data exfiltration, or remote code execution. Organizations must implement defense-in-depth strategies combining static analysis, runtime monitoring, and binary analysis to detect and mitigate these vulnerabilities.

Impact on Systems

• Compromise of Application Integrity: Predictable execution flow is disrupted
• Potential Data Exposure: Depending on context, sensitive configurations may leak
• Availability Risks: Unexpected states leading to temporary denial of service

Real-World Attack Scenario

An attacker probes the system interfaces to identify areas where the input or state related to Improper Input Validation is improperly handled. Once identified, they craft a payload tailored to the specific backend architecture. By exploiting the lack of robust structural validation, the attacker is able to force the application into an unintended state, bypassing standard business logic and achieving unauthorized outcomes.

Code Examples

Vulnerable Implementation

// VULNERABLE: Unvalidated input leading to Improper Input Validation
function processInput(data) {
    // Missing strict validation or sanitization
    executeOrStoreConfig(data);
}

Secure Alternative

// SECURE: Proper validation mitigating Improper Input Validation
function processInput(data) {
    if (!isValid(data)) throw new Error('Invalid input');
    const safeData = sanitize(data);
    executeOrStoreConfig(safeData);
}

Detection with Precogs AI

Precogs AI detects improper input validation patterns in both source code and compiled binaries by analyzing data flow from untrusted sources to sensitive sinks. Our binary analysis engine examines compiled artifacts without requiring source code access, identifying CWE-20 patterns in vendor software, containers, firmware, and third-party libraries.

Remediation

Implement proper software security controls following secure coding guidelines. Use automated scanning tools like Precogs AI to continuously monitor for CWE-20 vulnerabilities across your software supply chain. Apply the principle of least privilege and validate all inputs from untrusted sources.