What is Reliance on Obfuscation or Encryption (CWE-649)?

TL;DR: Reliance on Obfuscation or Encryption of Security-Relevant Inputs without Integrity Checking (CWE-649) is a vulnerability where security-relevant inputs are encrypted but not checked for integrity, leading to unexpected system states and incorrect decisions. Fix it by implementing PKI methods and verifying integrity.

What is Reliance on Obfuscation or Encryption of Security-Relevant Inputs without Integrity Checking?

Reliance on Obfuscation or Encryption of Security-Relevant Inputs without Integrity Checking (CWE-649) is a type of vulnerability where security-relevant inputs are encrypted but not checked for integrity. As defined by the MITRE Corporation under CWE-649, and classified by the OWASP Foundation as Not directly mapped.

Quick Summary

Reliance on Obfuscation or Encryption of Security-Relevant Inputs without Integrity Checking occurs when security-relevant inputs are obfuscated or encrypted but lack proper integrity checks, leading to potential tampering. This can result in unexpected system states and incorrect security decisions. Jump to: What is Reliance on Obfuscation or Encryption of Security-Relevant Inputs without Integrity Checking? · Quick Summary · Overview · How It Works · Business Impact · Attack Scenario · Detection · Fix · Framework-Specific Fixes · Ask AI · Best Practices Checklist · FAQ · Vulnerabilities Related

Jump to: Quick Summary · Reliance on Obfuscation or Encryption of Security-Relevant Inputs without Integrity Checking Overview · How Reliance on Obfuscation or Encryption of Security-Relevant Inputs without Integrity Checking Works · Business Impact of Reliance on Obfuscation or Encryption of Security-Relevant Inputs without Integrity Checking · Reliance on Obfuscation or Encryption of Security-Relevant Inputs without Integrity Checking Attack Scenario · How to Detect Reliance on Obfuscation or Encryption of Security-Relevant Inputs without Integrity Checking · How to Fix Reliance on Obfuscation or Encryption of Security-Relevant Inputs without Integrity Checking · Framework-Specific Fixes for Reliance on Obfuscation or Encryption of Security-Relevant Inputs without Integrity Checking · How to Ask AI to Check Your Code for Reliance on Obfuscation or Encryption of Security-Relevant Inputs without Integrity Checking · Reliance on Obfuscation or Encryption of Security-Relevant Inputs without Integrity Checking Best Practices Checklist · Reliance on Obfuscation or Encryption of Security-Relevant Inputs without Integrity Checking FAQ · Vulnerabilities Related to Reliance on Obfuscation or Encryption of Security-Relevant Inputs without Integrity Checking · References · Scan Your Own Site

Reliance on Obfuscation or Encryption of Security-Relevant Inputs without Integrity Checking Overview

What: A vulnerability where security-relevant inputs are encrypted but not checked for integrity. Why it matters: Without proper checks, encrypted data can be tampered with, leading to unexpected system states and incorrect decisions. Where it occurs: In applications that handle sensitive data via encryption without subsequent integrity verification. Who is affected: Developers who rely on encryption alone for security-relevant inputs. Who is NOT affected: Systems already using PKI methods or other robust integrity protection mechanisms.

How Reliance on Obfuscation or Encryption of Security-Relevant Inputs without Integrity Checking Works

Root Cause

The root cause lies in encrypting security-relevant inputs but failing to verify their integrity, allowing attackers to modify them undetected.

Attack Flow

1. Attacker identifies encrypted data that lacks integrity checks.
2. Modifies the data and sends it back to the application.
3. Application processes the modified data without detection.
4. System state becomes unexpected or security decisions are incorrect.

   Prerequisites to Exploit

   • Encrypted inputs must be mutable by an external actor.
   • No integrity verification is performed on these inputs.

     Vulnerable Code

     encrypted_input = encrypt(input_data)
     process(encrypted_input)
     

     This code demonstrates the absence of any integrity checks, allowing tampered data to pass through undetected.

Secure Code

signature = generate_signature(input_data)
validated_data = verify_integrity(input_data, signature)
if validated_data:
    process(validated_data)
else:
    raise ValueError("Integrity check failed")

This secure code ensures that the integrity of encrypted data is verified before processing it.

Business Impact of Reliance on Obfuscation or Encryption of Security-Relevant Inputs without Integrity Checking

Confidentiality

• Sensitive information can be exposed if tampered with.

  Integrity

• Unexpected system states and incorrect security decisions occur due to modified inputs.

  Availability

• System disruptions may arise from unexpected behavior caused by tampered data.

Business Consequences:

• Financial losses due to compromised data integrity.
• Compliance violations for failing to protect sensitive information.
• Damage to reputation from security incidents.

Reliance on Obfuscation or Encryption of Security-Relevant Inputs without Integrity Checking Attack Scenario

1. Attacker identifies an encrypted input that lacks integrity checks.
2. Modifies the encrypted value and sends it back to the application.
3. Application processes the modified data, leading to unexpected system states.
4. Incorrect security decisions are made based on tampered inputs.

How to Detect Reliance on Obfuscation or Encryption of Security-Relevant Inputs without Integrity Checking

Manual Testing

• Check for encryption functions used on security-relevant inputs.
• Ensure integrity checks (e.g., digital signatures) accompany encryption.
• Verify that there are no predictable patterns in tokens/parameters.
• Confirm account lockout mechanisms after repeated invalid requests.

Automated Scanners (SAST / DAST)

Static analysis can identify functions used for encryption without subsequent integrity verification. Dynamic testing is needed to confirm the absence of integrity checks during runtime.

PenScan Detection

PenScan’s automated scanners such as ZAP, Nuclei, and Wapiti detect this vulnerability by identifying encrypted data lacking integrity checks.

False Positive Guidance

A false positive occurs if an encryption function is present but correctly paired with an integrity check mechanism. Ensure that the code in question does not have a proper verification process.

How to Fix Reliance on Obfuscation or Encryption of Security-Relevant Inputs without Integrity Checking

• Protect important client controllable tokens/parameters for integrity using PKI methods.
• Implement checks for integrity on the server side.
• Lock out user accounts after repeated invalid requests.
• Ensure client-side tokens/parameters are unpredictable and not easily guessable.

Framework-Specific Fixes for Reliance on Obfuscation or Encryption of Security-Relevant Inputs without Integrity Checking

def process_secure_data(input_data):
    signature = generate_signature(input_data)
    if verify_integrity(input_data, signature):
        return process(input_data)
    else:
        raise ValueError("Integrity check failed")

How to Ask AI to Check Your Code for Reliance on Obfuscation or Encryption of Security-Relevant Inputs without Integrity Checking

Reliance on Obfuscation or Encryption of Security-Relevant Inputs without Integrity Checking Best Practices Checklist

✅ Protect important client controllable tokens/parameters for integrity using PKI methods. ✅ Implement checks for integrity on the server side. ✅ Lock out user accounts after repeated invalid requests. ✅ Ensure client-side tokens/parameters are unpredictable and not easily guessable. ✅ Use digital signatures to verify encrypted data’s integrity before processing.

Reliance on Obfuscation or Encryption of Security-Relevant Inputs without Integrity Checking FAQ

How does Reliance on Obfuscation or Encryption of Security-Relevant Inputs without Integrity Checking work?

It involves encrypting security-relevant inputs but failing to verify their integrity, allowing attackers to modify them undetected.

Why is it important to check for Reliance on Obfuscation or Encryption of Security-Relevant Inputs without Integrity Checking in your code?

Without proper integrity checks, encrypted data can be tampered with, leading to unexpected system states and incorrect security decisions.

Can you provide an example of how to detect Reliance on Obfuscation or Encryption of Security-Relevant Inputs without Integrity Checking manually?

Look for encryption functions used on security-relevant inputs without subsequent integrity checks like digital signatures.

How can I fix Reliance on Obfuscation or Encryption of Security-Relevant Inputs without Integrity Checking in my application?

Implement PKI methods to protect tokens/parameters and ensure server-side verification of their integrity.

What are the business consequences of failing to address Reliance on Obfuscation or Encryption of Security-Relevant Inputs without Integrity Checking?

Financial losses, compliance violations, and damage to reputation can result from compromised data integrity.

How does Reliance on Obfuscation or Encryption of Security-Relevant Inputs without Integrity Checking relate to other security weaknesses like CWE-345?

It is a specific variant of insufficient verification of data authenticity (CWE-345), focusing on encrypted inputs lacking integrity checks.

What are some common mistakes developers make when trying to prevent Reliance on Obfuscation or Encryption of Security-Relevant Inputs without Integrity Checking?

Relying solely on encryption, using predictable tokens, and failing to lock out accounts after repeated invalid requests are typical errors.

Vulnerabilities Related to Reliance on Obfuscation or Encryption of Security-Relevant Inputs without Integrity Checking

| CWE | Name | Relationship | |—|—|—| | CWE-345 | Insufficient Verification of Data Authenticity (ChildOf) |

References

• MITRE
• CAPEC-463
• NVD

Scan Your Own Site

Manual code review catches what you know to look for. An automated scan catches what you didn’t. Scan your own website using PenScan to find Reliance on Obfuscation or Encryption of Security-Relevant Inputs without Integrity Checking and other risks before an attacker does.