What is Improper Neutralization of Record (CWE-143)?

TL;DR: CWE-143 Improper Neutralization of Record Delimiters occurs when a product receives input from an upstream component but fails to neutralize or incorrectly neutralizes special elements that could be interpreted as record delimiters when sent to a downstream component.

At-a-Glance

What is Improper Neutralization of Record Delimiters?

Improper Neutralization of Record Delimiters (CWE-143) is a type of Security Misconfiguration vulnerability that occurs when a product receives input from an upstream component but fails to neutralize or incorrectly neutralizes special elements that could be interpreted as record delimiters when sent to a downstream component.

As defined by the MITRE Corporation under CWE-143, and classified by the OWASP Foundation under A9:2021 - Security Misconfiguration, Improper Neutralization of Record Delimiters is a critical vulnerability that can lead to unexpected state, data corruption, and system crashes if not addressed properly in software development.

Quick Summary

Improper Neutralization of Record Delimiters (CWE-143) is a type of Security Misconfiguration vulnerability that occurs when a product receives input from an upstream component but fails to neutralize or incorrectly neutralizes special elements that could be interpreted as record delimiters when sent to a downstream component. This can lead to unexpected state, data corruption, and system crashes if not addressed properly in software development.

Jump to: Quick Summary · Improper Neutralization of Record Delimiters Overview · How Improper Neutralization of Record Delimiters Works · Business Impact of Improper Neutralization of Record Delimiters · Improper Neutralization of Record Delimiters Attack Scenario · How to Detect Improper Neutralization of Record Delimiters · How to Fix Improper Neutralization of Record Delimiters · Framework-Specific Fixes for Improper Neutralization of Record Delimiters · How to Ask AI to Check Your Code for Improper Neutralization of Record Delimiters · Improper Neutralization of Record Delimiters Best Practices Checklist · Improper Neutralization of Record Delimiters FAQ · Vulnerabilities Related to Improper Neutralization of Record Delimiters · References · Scan Your Own Site

Improper Neutralization of Record Delimiters Overview

What

Improper Neutralization of Record Delimiters (CWE-143) is a type of Security Misconfiguration vulnerability that occurs when a product receives input from an upstream component but fails to neutralize or incorrectly neutralizes special elements that could be interpreted as record delimiters when sent to a downstream component.

Why it matters

Improper Neutralization of Record Delimiters can lead to unexpected state, data corruption, and system crashes if not addressed properly in software development. This is because the product may interpret the input as a record delimiter, which can cause the product to behave unexpectedly or crash.

Where it occurs

Improper Neutralization of Record Delimiters can occur in any product that receives input from an upstream component and sends it to a downstream component without proper neutralization of special elements.

Who is affected

Any product that uses record delimiters in its input processing may be affected by CWE-143 Improper Neutralization of Record Delimiters.

Who is NOT affected

Products that do not use record delimiters in their input processing are not affected by CWE-143 Improper Neutralization of Record Delimiters.

How Improper Neutralization of Record Delimiters Works

Root Cause

The root cause of CWE-143 Improper Neutralization of Record Delimiters is the failure to neutralize or incorrectly neutralizing special elements that could be interpreted as record delimiters when sent to a downstream component.

Attack Flow

1. The attacker sends input containing special elements that can be interpreted as record delimiters.
2. The product receives the input and fails to neutralize or incorrectly neutralizes the special elements.
3. The product interprets the input as a record delimiter, causing it to behave unexpectedly or crash.

Prerequisites to Exploit

• The attacker must send input containing special elements that can be interpreted as record delimiters.
• The product must fail to neutralize or incorrectly neutralize the special elements.

Vulnerable Code

import re

def process_input(input_str):
    # Fails to neutralize special elements
    output = re.sub(r'\n', '', input_str)
    return output

Secure Code

import re

def process_input(input_str):
    # Neutralizes special elements correctly
    output = re.sub(r'[\n\r]', '', input_str)
    return output

The secure code uses the re module to neutralize special elements, such as newline characters (\n) and carriage return characters (\r). This ensures that the product behaves correctly even when receiving input containing these special elements.

Business Impact of Improper Neutralization of Record Delimiters

Confidentiality

Improper Neutralization of Record Delimiters can lead to unexpected state, data corruption, and system crashes if not addressed properly in software development. This can compromise the confidentiality of sensitive data, as it may be exposed or corrupted during processing.

Integrity

Improper Neutralization of Record Delimiters can also compromise the integrity of data, as it may be modified or deleted during processing due to unexpected behavior or crashes.

Availability

Finally, Improper Neutralization of Record Delimiters can lead to system crashes or downtime, compromising the availability of critical systems and services.

Real-world business consequences:

• Financial losses due to data corruption or system crashes
• Compliance issues due to exposure of sensitive data
• Reputation damage due to compromised system availability

Improper Neutralization of Record Delimiters Attack Scenario

1. The attacker sends input containing special elements that can be interpreted as record delimiters.
2. The product receives the input and fails to neutralize or incorrectly neutralizes the special elements.
3. The product interprets the input as a record delimiter, causing it to behave unexpectedly or crash.

How to Detect Improper Neutralization of Record Delimiters

Manual Testing

• Review code for proper neutralization of special elements
• Test input containing special elements to ensure correct behavior

Automated Scanners (SAST / DAST)

• Use static analysis tools to identify potential vulnerabilities in code
• Use dynamic testing tools to simulate attacks and detect potential weaknesses

PenScan Detection

PenScan’s scanning engine actively tests for CWE-143 Improper Neutralization of Record Delimiters vulnerabilities.

False Positive Guidance

When reviewing findings from automated scanners or manual testing, ensure that the product is configured correctly and special elements are properly neutralized. Avoid false positives by considering context and configuration settings.

How to Fix Improper Neutralization of Record Delimiters

• Implement input validation to ensure special elements are not present in input
• Use output encoding to ensure special elements are properly escaped
• Properly configure record delimiters to prevent unexpected behavior or crashes

Framework-Specific Fixes for Improper Neutralization of Record Delimiters

# Python/Django example:
from django.core.exceptions import PermissionDenied

def process_input(input_str):
    # Validate input and escape special elements correctly
    if re.search(r'[\n\r]', input_str):
        raise PermissionDenied("Invalid input")
    output = re.sub(r'[\n\r]', '', input_str)
    return output

How to Ask AI to Check Your Code for Improper Neutralization of Record Delimiters

Review the following Python code block for potential CWE-143 Improper Neutralization of Record Delimiters vulnerabilities and rewrite it using proper neutralization of special elements:

import re

def process_input(input_str):
    # Fails to neutralize special elements
    output = re.sub(r'\n', '', input_str)
    return output

Rewrite the code using proper neutralization of special elements, such as the secure code example above.

Improper Neutralization of Record Delimiters Best Practices Checklist

✅ Implement input validation to ensure special elements are not present in input. ✅ Use output encoding to ensure special elements are properly escaped. ✅ Properly configure record delimiters to prevent unexpected behavior or crashes.

Improper Neutralization of Record Delimiters FAQ

How does Improper Neutralization of Record Delimiters occur?

Improper Neutralization of Record Delimiters occurs when a product receives input from an upstream component but fails to neutralize or incorrectly neutralizes special elements that could be interpreted as record delimiters when sent to a downstream component.

What are the common consequences of CWE-143 Improper Neutralization of Record Delimiters?

The common consequences of CWE-143 Improper Neutralization of Record Delimiters include unexpected state, which can lead to data corruption or system crashes.

How do I detect CWE-143 Improper Neutralization of Record Delimiters in my code?

You can detect CWE-143 Improper Neutralization of Record Delimiters using manual testing and automated scanners, such as PenScan’s scanning engine.

What are the best practices for preventing CWE-143 Improper Neutralization of Record Delimiters?

The best practices for preventing CWE-143 Improper Neutralization of Record Delimiters include input validation, output encoding, and proper configuration of record delimiters.

Can you provide a code example for fixing CWE-143 Improper Neutralization of Record Delimiters?

Yes, we can provide a code example for fixing CWE-143 Improper Neutralization of Record Delimiters using a specific programming language.

What are the related vulnerabilities to CWE-143 Improper Neutralization of Record Delimiters?

The related vulnerabilities to CWE-143 Improper Neutralization of Record Delimiters include CWE-140, which is a more general category that includes CWE-143 as a variant.

Where can I find more information about CWE-143 Improper Neutralization of Record Delimiters?

You can find more information about CWE-143 Improper Neutralization of Record Delimiters on the MITRE website and in various security documentation resources.

Vulnerabilities Related to Improper Neutralization of Record Delimiters

References

• MITRE CWE-143
• CAPEC
• 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 CWE-143 Improper Neutralization of Record Delimiters and other risks before an attacker does.