What is Missing Password Field Masking (CWE-549)?

TL;DR: Missing Password Field Masking (CWE-549) is a security vulnerability where web applications fail to mask password inputs, increasing the risk of unauthorized access. Fix it by ensuring all password fields use type=”password”.

What is Missing Password Field Masking?

Missing Password Field Masking (CWE-549) is a type of security vulnerability that occurs when password fields in web applications are not masked, increasing the risk of passwords being observed and captured. As defined by the MITRE Corporation under CWE-549, this weakness can lead to unauthorized access and data breaches if sensitive information is exposed in clear text.

Quick Summary

Missing Password Field Masking (CWE-549) occurs when web applications fail to mask password fields during entry, making it easier for attackers to observe and capture passwords. This vulnerability significantly increases the risk of unauthorized access and can lead to serious data breaches if sensitive information is exposed in clear text.

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

Missing Password Field Masking Overview

What

Missing Password Field Masking (CWE-549) is a security vulnerability where web applications fail to mask password fields during entry, increasing the risk of passwords being observed and captured.

Why it matters

This weakness can lead to unauthorized access and data breaches by exposing sensitive information in clear text. It significantly increases the risk of attackers capturing user credentials and gaining unauthorized access to systems.

Where it occurs

This vulnerability commonly affects web applications that do not properly mask password fields during entry, such as HTML forms with type=”text” instead of type=”password”.

Who is affected

Web application users whose passwords are entered in unmasked fields are at risk of having their credentials observed and captured by attackers.

Who is NOT affected

Applications that enforce masking of password fields using type=”password” or similar mechanisms are not vulnerable to this weakness.

How Missing Password Field Masking Works

Root Cause

The root cause of Missing Password Field Masking (CWE-549) is the failure to properly mask password fields during entry, making it easier for attackers to observe and capture passwords.

Attack Flow

1. An attacker observes a user entering their password in an unmasked field.
2. The attacker captures the entered password by observing or intercepting the input.
3. The captured password can then be used to gain unauthorized access to the system.

Prerequisites to Exploit

• Web application must have unmasked password fields (type=”text” instead of type=”password”).
• User must enter a password in an observable manner.

Vulnerable Code

<input type="text" name="password">

This code snippet demonstrates an unsecured password field that does not mask user input, making it vulnerable to observation and capture by attackers.

Secure Code

<input type="password" name="password">

The secure version of the code ensures that all password fields use type="password" to properly mask user input during entry.

Business Impact of Missing Password Field Masking

Confidentiality

• Exposes sensitive information such as passwords in clear text, increasing the risk of unauthorized access and data breaches.

Integrity

• None directly impacted by this weakness.

Availability

• None directly impacted by this weakness.

Real-world Consequences

• Financial losses due to compromised user accounts.
• Compliance violations if sensitive data is exposed.
• Damage to reputation and trust from data breaches.

Missing Password Field Masking Attack Scenario

1. An attacker observes a user entering their password in an unmasked field on a web application.
2. The attacker captures the entered password by observing or intercepting the input.
3. The captured password can then be used to gain unauthorized access to the system, leading to potential data breaches and financial losses.

How to Detect Missing Password Field Masking

Manual Testing

• Inspect HTML forms for unmasked password fields (type=”text” instead of type=”password”).
• Verify that all client-side code enforces masking of password fields.
• Check server-side validation mechanisms to ensure they enforce proper field types.

Automated Scanners (SAST / DAST)

Static analysis can detect unmasked password fields in HTML forms, while dynamic testing can observe actual user interactions and identify vulnerabilities during runtime.

PenScan Detection

PenScan’s automated scanners use techniques like ZAP and Nuclei to check for missing password field masking by inspecting HTML forms and validating input types.

False Positive Guidance

False positives may occur if the scanner detects a text field used for non-sensitive information, such as a username or email address. Ensure that only actual password fields are flagged.

How to Fix Missing Password Field Masking

• Require all password fields in your web application be masked using type="password" to prevent other users from seeing entered credentials.
• Implement server-side validation to ensure proper field types are enforced across the entire application.

Framework-Specific Fixes for Missing Password Field Masking

Python/Django

from django import forms

class LoginForm(forms.Form):
    password = forms.CharField(widget=forms.PasswordInput)

This code ensures that all password fields use PasswordInput to mask user input during entry, preventing observation and capture by attackers.

How to Ask AI to Check Your Code for Missing Password Field Masking

Missing Password Field Masking Best Practices Checklist

• ✅ Ensure all password fields use type="password" to mask user input during entry.
• ✅ Implement server-side validation to enforce proper field types across the entire application.
• ✅ Verify that client-side JavaScript does not inadvertently expose unmasked passwords.

Missing Password Field Masking FAQ

How does missing password field masking work?

Missing password field masking occurs when a web application fails to mask user input for passwords, making it easier for attackers to observe and capture sensitive information.

What are the consequences of missing password field masking?

This vulnerability can lead to unauthorized access, compromising confidentiality by exposing passwords in clear text.

How do I detect missing password field masking manually?

Manually inspect HTML forms for input fields with type=”text” instead of type=”password”.

What are the common mitigation strategies for missing password field masking?

Ensure all password fields use type=”password”, and validate that this is enforced across all client-side and server-side code.

How do I prevent missing password field masking in my web application?

Implement a requirement that all password fields be masked to prevent other users from seeing the entered information.

What are the business impacts of missing password field masking?

This vulnerability can lead to financial losses, compliance violations, and damage to reputation if sensitive data is compromised.

How does PenScan detect missing password field masking?

PenScan’s automated scanners check for HTML forms with unmasked password fields using static analysis techniques.

Vulnerabilities Related to Missing Password Field Masking

References

• MITRE: CWE-549
• 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 Missing Password Field Masking and other risks before an attacker does.