How to Block Zip Bombs and Other Unsafe Archives using Node.js

Cloudmersive
3 min readMay 16, 2023

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Compressed archives overloaded with immense quantities of data (often referred to as “Zip Bombs”) can crash your entire system when they’re opened, resulting in a widespread Denial of Service across your entire system. While virus and malware threats often attract more attention in the public discourse on file upload security, Zip Bombs and other unsafe archives pose an equally serious threat and need to be detected quickly in any file upload process.

Thankfully, you can quickly & easily configure a policy against unsafe archive uploads using the ready-to-run Node.js code examples provided below. Just set the allowUnsafeArchives Boolean to “False,” and your archive file uploads will be thoroughly vetted for unsafe content. Files containing unsafe archives will receive a CleanResult: False Boolean in the API response body, allowing you to easily quarantine or delete those files.

You can install the Node.js SDK using npm install by running the command below:

npm install cloudmersive-virus-api-client --save

After that, you can structure your API call with the below Node.js examples:

var CloudmersiveVirusApiClient = require('cloudmersive-virus-api-client');
var defaultClient = CloudmersiveVirusApiClient.ApiClient.instance;

// Configure API key authorization: Apikey
var Apikey = defaultClient.authentications['Apikey'];
Apikey.apiKey = 'YOUR API KEY';



var apiInstance = new CloudmersiveVirusApiClient.ScanApi();

var inputFile = Buffer.from(fs.readFileSync("C:\\temp\\inputfile").buffer); // File | Input file to perform the operation on.

var opts = {
'allowExecutables': true, // Boolean | Set to false to block executable files (program code) from being allowed in the input file. Default is false (recommended).
'allowInvalidFiles': true, // Boolean | Set to false to block invalid files, such as a PDF file that is not really a valid PDF file, or a Word Document that is not a valid Word Document. Default is false (recommended).
'allowScripts': true, // Boolean | Set to false to block script files, such as a PHP files, Python scripts, and other malicious content or security threats that can be embedded in the file. Set to true to allow these file types. Default is false (recommended).
'allowPasswordProtectedFiles': true, // Boolean | Set to false to block password protected and encrypted files, such as encrypted zip and rar files, and other files that seek to circumvent scanning through passwords. Set to true to allow these file types. Default is false (recommended).
'allowMacros': true, // Boolean | Set to false to block macros and other threats embedded in document files, such as Word, Excel and PowerPoint embedded Macros, and other files that contain embedded content threats. Set to true to allow these file types. Default is false (recommended).
'allowXmlExternalEntities': true, // Boolean | Set to false to block XML External Entities and other threats embedded in XML files, and other files that contain embedded content threats. Set to true to allow these file types. Default is false (recommended).
'allowInsecureDeserialization': true, // Boolean | Set to false to block Insecure Deserialization and other threats embedded in JSON and other object serialization files, and other files that contain embedded content threats. Set to true to allow these file types. Default is false (recommended).
'allowHtml': true, // Boolean | Set to false to block HTML input in the top level file; HTML can contain XSS, scripts, local file accesses and other threats. Set to true to allow these file types. Default is false (recommended) [for API keys created prior to the release of this feature default is true for backward compatability].
'restrictFileTypes': "restrictFileTypes_example" // String | Specify a restricted set of file formats to allow as clean as a comma-separated list of file formats, such as .pdf,.docx,.png would allow only PDF, PNG and Word document files. All files must pass content verification against this list of file formats, if they do not, then the result will be returned as CleanResult=false. Set restrictFileTypes parameter to null or empty string to disable; default is disabled.
};

var callback = function(error, data, response) {
if (error) {
console.error(error);
} else {
console.log('API called successfully. Returned data: ' + data);
}
};
apiInstance.scanFileAdvanced(inputFile, opts, callback);

Now you’ll just need to provide a free-tier API key for authentication, and you’re good to go!

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Cloudmersive
Cloudmersive

Written by Cloudmersive

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