Rule Definition
When a resource is not released after use, it can allow attackers to cause a denial of service by causing the allocation of resources without triggering their release. Frequently-affected resources include memory, CPU, disk space, power or battery, etc.

Remediation
Always close a filesystem after using open. Always use closeSync after using openSync.

Violation Code Sample

import * as fs from 'fs';

// NOT VIOLATION 
fs.readFile('/etc/passwd', (err, data) => { 
  if (err) throw err; 
  console.log(data); 
}); 

// VIOLATION 
fs.open('myfile', 'wx', (err, fd) => { 
  if (err) { 
    if (err.code === 'EEXIST') { 
      console.error('myfile already exists'); 
      return; 
    } 

    throw err; 
  } 

  writeMyData(fd); 
});

Fixed Code Sample

import * as fs from 'fs';

fs.open('myfile', 'wx', (err, fd) => { 
  if (err) { 
    if (err.code === 'EEXIST') { 
      console.error('myfile already exists'); 
      return; 
    } 

    throw err; 
  } 

  writeMyData(fd); 
  fs.close(fd, function(error) {}) 
});

https://nodejs.org/api/fs.html OMG CISQ Recommendation: ASCRM-CWE-772 and ASCSM-CWE-772