How to Protect Against XSS Attacks in Java
Detects and removes XSS (Cross-Site-Scripting) attacks from text input through normalization.
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Join For FreeCross-Site Scripting (XSS) attacks are a form of threat that takes advantage of vulnerabilities in web applications to prey on user information. Using malicious scripts, attackers can reach different users through a usually trustworthy web page and access any information logged in the browser by the user including cookies and other sensitive information. These kinds of attacks can occur wherever a web program accepts user input without validation and subsequently uses it within its output.
It is important to take all necessary steps toward protecting your users, and this is especially true in the case of XSS attacks, as a user may only be aware of their use of your website, and not the malicious actor who is threatening them. This can then harm your website’s reputation as users will relate any issues to its users and may be disinclined to return.
The following APIs will allow you to protect against XSS attacks by not only checking and validating any input text but also removes any detected attacks through normalization. The goal of implementing these APIs is to protect not only your users but also the legitimacy and reputation of your business.
To use any of the following APIs, you will first need to install the SDK library using Maven by adding a Jitpack reference to the repository in pom.xml:
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<repositories>
<repository>
<id>jitpack.io</id>
<url>https://jitpack.io</url>
</repository>
</repositories>
Then, we can add a reference to the dependency:
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<dependencies>
<dependency>
<groupId>com.github.Cloudmersive</groupId>
<artifactId>Cloudmersive.APIClient.Java</artifactId>
<version>v3.54</version>
</dependency>
</dependencies>
The first API will check any user-facing text input for XSS attacks. This is useful for detecting threats before they are carried out. To run the API, install the SDK as shown above and call the function:
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// Import classes:
//import com.cloudmersive.client.invoker.ApiClient;
//import com.cloudmersive.client.invoker.ApiException;
//import com.cloudmersive.client.invoker.Configuration;
//import com.cloudmersive.client.invoker.auth.*;
//import com.cloudmersive.client.TextInputApi;
ApiClient defaultClient = Configuration.getDefaultApiClient();
// Configure API key authorization: Apikey
ApiKeyAuth Apikey = (ApiKeyAuth) defaultClient.getAuthentication("Apikey");
Apikey.setApiKey("YOUR API KEY");
// Uncomment the following line to set a prefix for the API key, e.g. "Token" (defaults to null)
//Apikey.setApiKeyPrefix("Token");
TextInputApi apiInstance = new TextInputApi();
String value = "value_example"; // String | User-facing text input.
try {
XssProtectionResult result = apiInstance.textInputCheckXss(value);
System.out.println(result);
} catch (ApiException e) {
System.err.println("Exception when calling TextInputApi#textInputCheckXss");
e.printStackTrace();
}
This will return the original input, the normalized result, whether the validation was successful, and whether the input contained an XSS attack. To ensure that this API works properly, you need to check that certain requirements are met:
- The text string was input correctly.
- You have input your API Key. This can be retrieved at no cost on the Cloudmersive website, providing 800 monthly calls across our API library.
The second API goes a step further, by both detecting and removing any XSS attacks from text input. This is performed through normalization, which removes all duplicate or unrecognized scripts from a text string. Install the SDK the begin running the API, and then call the function:
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// Import classes:
//import com.cloudmersive.client.invoker.ApiClient;
//import com.cloudmersive.client.invoker.ApiException;
//import com.cloudmersive.client.invoker.Configuration;
//import com.cloudmersive.client.invoker.auth.*;
//import com.cloudmersive.client.TextInputApi;
ApiClient defaultClient = Configuration.getDefaultApiClient();
// Configure API key authorization: Apikey
ApiKeyAuth Apikey = (ApiKeyAuth) defaultClient.getAuthentication("Apikey");
Apikey.setApiKey("YOUR API KEY");
// Uncomment the following line to set a prefix for the API key, e.g. "Token" (defaults to null)
//Apikey.setApiKeyPrefix("Token");
TextInputApi apiInstance = new TextInputApi();
String value = "value_example"; // String | User-facing text input.
try {
XssProtectionResult result = apiInstance.textInputProtectXss(value);
System.out.println(result);
} catch (ApiException e) {
System.err.println("Exception when calling TextInputApi#textInputProtectXss");
e.printStackTrace();
}
This returns a similar output as the previous API but with any detected XSS attacks removed.
The final API performs the same functions are the two previous examples but can be used to check multiple inputs as a batch. The parameters for this API should be a list of the input text items in your preferred order of operation. Install the SDK library as with the two previous API and call the function:
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// Import classes:
//import com.cloudmersive.client.invoker.ApiClient;
//import com.cloudmersive.client.invoker.ApiException;
//import com.cloudmersive.client.invoker.Configuration;
//import com.cloudmersive.client.invoker.auth.*;
//import com.cloudmersive.client.TextInputApi;
ApiClient defaultClient = Configuration.getDefaultApiClient();
// Configure API key authorization: Apikey
ApiKeyAuth Apikey = (ApiKeyAuth) defaultClient.getAuthentication("Apikey");
Apikey.setApiKey("YOUR API KEY");
// Uncomment the following line to set a prefix for the API key, e.g. "Token" (defaults to null)
//Apikey.setApiKeyPrefix("Token");
TextInputApi apiInstance = new TextInputApi();
XssProtectionBatchRequest value = new XssProtectionBatchRequest(); // XssProtectionBatchRequest | User-facing text input.
try {
XssProtectionBatchResponse result = apiInstance.textInputCheckXssBatch(value);
System.out.println(result);
} catch (ApiException e) {
System.err.println("Exception when calling TextInputApi#textInputCheckXssBatch");
e.printStackTrace();
}
This will return the same output as the previous two APIs combined, with one result for each string in the order of input.
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