Uncommon query string parameter

Rejah Rehim
Published on
23 Apr 2024
7 min read

There are applications that supply multiple HTTP parameters with the same name. This method to supply HTTP parameters might cause the application to interpret values in an unanticipated way.

By exploiting this bug, an attacker can easily bypass any input validation. The attacker can also modify the internal variables of the application to trigger internal application error.

These conditions can cause catastrophic effects on the server. If query strings are not passed securely to the URL, the attacker can get sensitive information about the user and the application. The sensitive information includes usernames, passwords, tokens (authX), database details, and the other potentially sensitive data.


The following link is an example of a query string.


An “Uncommon query string parameter” typically refers to a parameter included in a URL’s query string that is not commonly seen or recognized.

In web development, query string parameters are used to pass information between a web server and a client browser.

They are appended to the end of a URL after a question mark (?), and multiple parameters are separated by ampersands (&).

Common examples of query string parameters include those used for filtering search results, tracking user sessions, or passing data between web pages.

These parameters may serve various purposes, such as customization, analytics, or functionality specific to the application. However, they might not adhere to common conventions or standards observed across the web.

In some cases, including uncommon query string parameters in URLs might be a deliberate choice made by developers to achieve specific functionality or to track certain user behaviors.

However, it’s essential to handle these parameters securely and ensure they do not pose any security risks such as injection attacks or unintended data exposure.

Overall, the term “uncommon query string parameter” simply denotes a parameter in a URL’s query string that is not widely recognized or standardized across web applications.

What are the impacts of uncommon query string parameters?

The impacts of uncommon query string parameters can vary depending on how they are used and implemented within a web application. Here are some potential impacts:

1. Compatibility issues

Uncommon query string parameters might not be recognized or properly handled by all web servers, browsers, or client-side scripts. This can lead to compatibility issues, where certain functionality or features of the application may not work as intended for some users.

2. Security risks

If uncommon query string parameters are not properly validated and sanitized, they can pose security risks such as injection attacks (e.g., SQL injection, XSS) or unintended data exposure.

Attackers may attempt to manipulate these parameters to exploit vulnerabilities in the application and gain unauthorized access to sensitive information or perform malicious actions.

3. User experience

Including unnecessary or confusing query string parameters can impact the user experience negatively. Users may find URLs with long or cryptic query strings difficult to understand or share, leading to frustration and decreased engagement with the application.

4. Performance overhead

Large or complex query strings, including uncommon parameters, can increase the size of HTTP requests, leading to performance overhead, particularly for users with limited bandwidth or slower network connections.

This can result in slower page load times and decreased overall performance of the application.

5. Maintenance challenges

Uncommon query string parameters may complicate the maintenance and evolution of the application over time.

Developers may find it challenging to understand and modify code that relies on these parameters, especially if they are poorly documented or not consistently used throughout the application.

6. Analytics and tracking

Uncommon query string parameters may be used for analytics or tracking purposes to monitor user behavior, track marketing campaigns, or gather other insights. You can also use social media analytics tools to analyze these parameters and gain a deeper understanding of how users interact with your content across different platforms.

However, if these parameters are not properly managed or secured, they may lead to inaccurate or unreliable data, affecting decision-making processes based on analytics.

7. SEO considerations

URL structure, including query string parameters, can impact search engine optimization (SEO).

Uncommon query string parameters that are not relevant to content or user experience may dilute the effectiveness of SEO efforts or confuse search engine crawlers, potentially affecting the visibility and ranking of the application in search engine results.

Overall, while uncommon query string parameters may have legitimate uses within web applications, it’s essential to carefully consider their impacts on security, usability, performance, and maintenance, and to implement appropriate measures to mitigate any associated risks.

How can you prevent the consequences of uncommon query string parameters?

Preventing the misuse or unintended consequences of uncommon query string parameters involves implementing several best practices in web development and security. Here’s how you can prevent potential issues:

1. Validation and sanitization

Always validate and sanitize query string parameters on the server-side to ensure they adhere to expected formats and values. Reject or sanitize any parameters that contain unexpected or potentially harmful characters to prevent injection attacks such as SQL injection or XSS.

2. Documentation

Document all query string parameters used in your web application, including both common and uncommon ones.

Provide clear explanations of their purposes, expected values, and any restrictions or validation rules that apply. This documentation helps developers understand and use parameters correctly, reducing the likelihood of misuse or misunderstanding.

3. Standardization

Establish and adhere to a standard naming convention for query string parameters across your application.

Consistent naming conventions make it easier for developers to understand and work with parameters, promote code readability, and reduce the risk of conflicts or confusion between different parts of the application.

4. Limitation of exposure

Minimize the exposure of uncommon query string parameters by using them only when necessary and avoiding unnecessary proliferation of parameters.

Consider alternative methods for passing data between components of your application, such as using session variables, cookies, or server-side storage, if appropriate.

5. Security controls

Implement security controls to protect against misuse or abuse of query string parameters, such as rate limiting, input validation, and access controls.

Restrict access to sensitive functionality or resources based on the presence or values of specific parameters to prevent unauthorized actions.

6. Testing and auditing

Conduct thorough testing and security audits of your web application to identify and remediate any vulnerabilities or weaknesses related to query string parameters.

Test your application under various scenarios, including edge cases and potential abuse scenarios, to ensure robustness and resilience against attacks.

7. Monitoring and logging

Monitor and log the usage of query string parameters in your application to detect suspicious or anomalous activity. Implement logging mechanisms to record details such as parameter values, user interactions, and errors for analysis and investigation purposes.

8. Educating developers

Educate developers on the risks and best practices associated with query string parameters and web security in general. Provide training and resources to help them understand how to use parameters securely and responsibly within the context of your application.

By following these preventive measures, you can mitigate the risks associated with uncommon query string parameters and ensure the security, reliability, and maintainability of your web application.

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Written by
Rejah Rehim
Rejah Rehim
Co-founder, Director
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