Application error disclosure

Nash N Sulthan
Published on
08 Apr 2024
6 min read

An application error disclosure is an attack where an application cannot protect the user’s data.

This attack will help an attacker to successfully access all the information about the application which includes information about the server environment, credentials of API keys, and many more.

These leakages can have disastrous effects on the server. The application error disclosure has following types:

1. Banner grabbing

Here, an attacker sends different requests to the server. These requests are attempts to leak information about the server.

If the server configurations are not securely implemented, it will leak information like PHP version, ASP version and many more.

Depending on these software’s versions, an attacker can exploit the server for sensitive information. eg: If a server has older PHP versions, it will most probably be vulnerable to remote command injection.

2. Source code disclosure

This type of attack involves an attacker having access to the application’s source code. Using the source code, an attacker can perform white box testing on the application.

This type of attack is also called white box testing because the attacker has read the code and is performing attacks based on the code’s logical error.

The source code might get leaked if the git repository of the application might have gone public.

3. The file name and path disclosure

This attack involves an attacker having access to file names or paths that expose the application’s structure.

This attack is possible if there are loopholes in the backend, improper handling of data and man more.


An attacker can send a malicious database request to the server. If the application is vulnerable to application error disclosure attack, the response will be as follows.

Microsoft OLE DB Provider for ODBC Drivers (0x80004005) ‘

[MySQL][ODBC 3.51 Driver] Unknown MySQL server host

The above output will help an attacker to understand the database of the application more precisely.

The attacker will test the application with many other cases till he can successfully exploit the web application.

What are the impacts of application error disorder?

Application error disclosure can have several negative impacts on both the security and user experience of a system.

Here are some of the key impacts:

1. Information leakage

Error messages often contain technical details about the system’s infrastructure, code, or configuration.

This information can be valuable to attackers as it provides insights into potential vulnerabilities or weak points in the system.

2. Security risks

Attackers can exploit error messages to gain knowledge about the system’s inner workings and potentially launch targeted attacks.

For example, they might discover a misconfigured server, outdated software, or vulnerable endpoints.

3. Data exposure

In some cases, error messages may inadvertently reveal sensitive data, such as database connection strings, API keys, or user credentials.

This can lead to data breaches or unauthorized access.

4. User frustration

Error messages that are too technical or vague can frustrate users. They might not understand the issue, leading to poor user experience.

Users may also be exposed to potentially misleading information.

5. Reduced trust

Repeated or poorly handled error disclosures can erode user trust in the application. Users may perceive it as unreliable or insecure, damaging the reputation of the service or website.

6. Compliance issues

In regulated industries like healthcare or finance, revealing errors can lead to compliance violations.

Certain regulations, such as HIPAA or GDPR, require the protection of user data and system information.

7. Increased attack surface

Attackers can use disclosed error information to refine their attacks, potentially creating new vulnerabilities or avenues for exploitation.

How can you prevent application error disclosure?

Preventing and mitigating application error disclosure is crucial for enhancing the security of your application and providing a better user experience. Here are several steps you can take:

1. Custom error handling

Implement custom error messages for your application. These messages should be user-friendly and not reveal technical details.

Instead of exposing code errors or database query issues, provide a generic error message.

2. Logging and monitoring

Log error messages securely. Store them in a location that is not publicly accessible and ensure that only authorized personnel can access error logs.

Set up monitoring and alerting systems to notify you when specific error patterns or thresholds are reached. This allows you to address issues promptly.

3. Detailed errors for development environments only

In development and staging environments, you may want more detailed error messages to assist with debugging.

In these environments, you can configure the application to display detailed errors, but ensure they are disabled in production.

4. Use proper error codes

Assign error codes to different types of errors rather than exposing detailed error messages.

These codes can be logged internally for debugging purposes while displaying a user-friendly message to users.

5. Rate limiting

Implement rate limiting for error messages to prevent attackers from flooding your application with requests that could lead to error disclosure.

6. Securely handle unhandled errors

Make sure that unhandled exceptions or errors are gracefully handled to prevent exposure stack traces or other sensitive information.

7. Input validation

Ensure that user inputs are properly validated and sanitized to prevent errors caused by unexpected or malicious input.

8. Security headers

Use security headers like Content Security Policy (CSP) and X-Content-Type-Options to add an extra layer of protection against certain types of attacks.

9. Third-party libraries and components

Keep third-party libraries and components up to date, as they can also introduce vulnerabilities and errors.

10. Penetration testing and code audits

Regularly conduct penetration testing and code audits to identify and fix security vulnerabilities, including error disclosure issues. Using platforms such as Beagle Security can help you assess your security standing, and also mitigate future vulnerabilities.

By following these practices, you can significantly reduce the risk of application error disclosure and provide a more secure and user-friendly experience for your application’s users.

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Written by
Nash N Sulthan
Nash N Sulthan
Cyber Security Lead Engineer
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