Version Details and Security Vulnerabilities

Impact

This vulnerability impacts npm (server) users of moment.js, especially if user provided locale string, eg fr is directly used to switch moment locale.

Patches

This problem is patched in 2.29.2, and the patch can be applied to all affected versions (from 1.0.1 up until 2.29.1, inclusive).

Workarounds

Sanitize user-provided locale name before passing it to moment.js.

References

Are there any links users can visit to find out more?

For more information

If you have any questions or comments about this advisory:

• Open an issue in moment repo

Impact

• using string-to-date parsing in moment (more specifically rfc2822 parsing, which is tried by default) has quadratic (N^2) complexity on specific inputs
• noticeable slowdown is observed with inputs above 10k characters
• users who pass user-provided strings without sanity length checks to moment constructor are vulnerable to (Re)DoS attacks

Patches

The problem is patched in 2.29.4, the patch can be applied to all affected versions with minimal tweaking.

Workarounds

In general, given the proliferation of ReDoS attacks, it makes sense to limit the length of the user input to something sane, like 200 characters or less. I haven't seen legitimate cases of date-time strings longer than that, so all moment users who do pass a user-originating string to constructor are encouraged to apply such a rudimentary filter, that would help with this but also most future ReDoS vulnerabilities.

References

There is an excellent writeup of the issue here: https://github.com/moment/moment/pull/6015#issuecomment-1152961973=

Details

The issue is rooted in the code that removes legacy comments (stuff inside parenthesis) from strings during rfc2822 parsing. moment("(".repeat(500000)) will take a few minutes to process, which is unacceptable.

A vulnerability classified as problematic has been found in debug-js debug up to 3.0.x. This affects the function useColors of the file src/node.js. The manipulation of the argument str leads to inefficient regular expression complexity. Upgrading to version 3.1.0 is able to address this issue. The name of the patch is c38a0166c266a679c8de012d4eaccec3f944e685. It is recommended to upgrade the affected component. The identifier VDB-217665 was assigned to this vulnerability. The patch has been backported to the 2.6.x branch in version 2.6.9.

Affected versions of debug are vulnerable to regular expression denial of service when untrusted user input is passed into the o formatter.

As it takes 50,000 characters to block the event loop for 2 seconds, this issue is a low severity issue.

This was later re-introduced in version v3.2.0, and then repatched in versions 3.2.7 and 4.3.1.

Recommendation

Version 2.x.x: Update to version 2.6.9 or later. Version 3.1.x: Update to version 3.1.0 or later. Version 3.2.x: Update to version 3.2.7 or later. Version 4.x.x: Update to version 4.3.1 or later.

A vulnerability was found in diff before v3.5.0, the affected versions of this package are vulnerable to Regular Expression Denial of Service (ReDoS) attacks.

Affected versions of sync-exec use files located in /tmp/ to buffer command results before returning values. As /tmp/ is almost always set with world readable permissions, this may allow low privilege users on the system to read the results of commands run via sync-exec under a higher privilege user.

Recommendation

There is currently no direct patch for sync-exec, as the child_process.execSync function provided in Node.js v0.12.0 and later provides the same functionality natively.

The best mitigation currently is to update to Node.js v0.12.0 or later, and migrate all uses of sync-exec to child_process.execSync().

Versions 4.3.1 and earlier of semver are affected by a regular expression denial of service vulnerability when extremely long version strings are parsed.

Recommendation

Update to version 4.3.2 or later

Versions of the package semver before 7.5.2 on the 7.x branch, before 6.3.1 on the 6.x branch, and all other versions before 5.7.2 are vulnerable to Regular Expression Denial of Service (ReDoS) via the function new Range, when untrusted user data is provided as a range.

All versions of defaults-deep are vulnerable to prototype pollution. Provided certain input defaults-deep can add or modify properties of the Object prototype. These properties will be present on all objects.

Recommendation

As no patch is currently available for this vulnerability it is our recommendation to select another module that can provide this functionality.

The parse method of the JSON5 library before and including version 2.2.1 does not restrict parsing of keys named __proto__, allowing specially crafted strings to pollute the prototype of the resulting object.

This vulnerability pollutes the prototype of the object returned by JSON5.parse and not the global Object prototype, which is the commonly understood definition of Prototype Pollution. However, polluting the prototype of a single object can have significant security impact for an application if the object is later used in trusted operations.

Impact

This vulnerability could allow an attacker to set arbitrary and unexpected keys on the object returned from JSON5.parse. The actual impact will depend on how applications utilize the returned object and how they filter unwanted keys, but could include denial of service, cross-site scripting, elevation of privilege, and in extreme cases, remote code execution.

Mitigation

This vulnerability is patched in json5 v2.2.2 and later. A patch has also been backported for json5 v1 in versions v1.0.2 and later.

Details

Suppose a developer wants to allow users and admins to perform some risky operation, but they want to restrict what non-admins can do. To accomplish this, they accept a JSON blob from the user, parse it using JSON5.parse, confirm that the provided data does not set some sensitive keys, and then performs the risky operation using the validated data:

const JSON5 = require('json5');

const doSomethingDangerous = (props) => {
  if (props.isAdmin) {
    console.log('Doing dangerous thing as admin.');
  } else {
    console.log('Doing dangerous thing as user.');
  }
};

const secCheckKeysSet = (obj, searchKeys) => {
  let searchKeyFound = false;
  Object.keys(obj).forEach((key) => {
    if (searchKeys.indexOf(key) > -1) {
      searchKeyFound = true;
    }
  });
  return searchKeyFound;
};

const props = JSON5.parse('{"foo": "bar"}');
if (!secCheckKeysSet(props, ['isAdmin', 'isMod'])) {
  doSomethingDangerous(props); // "Doing dangerous thing as user."
} else {
  throw new Error('Forbidden...');
}

If the user attempts to set the isAdmin key, their request will be rejected:

const props = JSON5.parse('{"foo": "bar", "isAdmin": true}');
if (!secCheckKeysSet(props, ['isAdmin', 'isMod'])) {
  doSomethingDangerous(props);
} else {
  throw new Error('Forbidden...'); // Error: Forbidden...
}

However, users can instead set the __proto__ key to {"isAdmin": true}. JSON5 will parse this key and will set the isAdmin key on the prototype of the returned object, allowing the user to bypass the security check and run their request as an admin:

const props = JSON5.parse('{"foo": "bar", "__proto__": {"isAdmin": true}}');
if (!secCheckKeysSet(props, ['isAdmin', 'isMod'])) {
  doSomethingDangerous(props); // "Doing dangerous thing as admin."
} else {
  throw new Error('Forbidden...');
}

Versions of lodash before 4.17.12 are vulnerable to Prototype Pollution. The function defaultsDeep allows a malicious user to modify the prototype of Object via {constructor: {prototype: {...}}} causing the addition or modification of an existing property that will exist on all objects.

Recommendation

Update to version 4.17.12 or later.

Versions of lodash before 4.17.5 are vulnerable to prototype pollution.

The vulnerable functions are 'defaultsDeep', 'merge', and 'mergeWith' which allow a malicious user to modify the prototype of Object via __proto__ causing the addition or modification of an existing property that will exist on all objects.

Recommendation

Update to version 4.17.5 or later.

Versions of lodash before 4.17.11 are vulnerable to prototype pollution.

The vulnerable functions are 'defaultsDeep', 'merge', and 'mergeWith' which allow a malicious user to modify the prototype of Object via {constructor: {prototype: {...}}} causing the addition or modification of an existing property that will exist on all objects.

Recommendation

Update to version 4.17.11 or later.

lodash prior to 4.7.11 is affected by: CWE-400: Uncontrolled Resource Consumption. The impact is: Denial of service. The component is: Date handler. The attack vector is: Attacker provides very long strings, which the library attempts to match using a regular expression. The fixed version is: 4.7.11.

All versions of package lodash prior to 4.17.21 are vulnerable to Regular Expression Denial of Service (ReDoS) via the toNumber, trim and trimEnd functions.

Steps to reproduce (provided by reporter Liyuan Chen):

var lo = require('lodash');

function build_blank(n) {
    var ret = "1"
    for (var i = 0; i < n; i++) {
        ret += " "
    }
    return ret + "1";
}
var s = build_blank(50000) var time0 = Date.now();
lo.trim(s) 
var time_cost0 = Date.now() - time0;
console.log("time_cost0: " + time_cost0);
var time1 = Date.now();
lo.toNumber(s) var time_cost1 = Date.now() - time1;
console.log("time_cost1: " + time_cost1);
var time2 = Date.now();
lo.trimEnd(s);
var time_cost2 = Date.now() - time2;
console.log("time_cost2: " + time_cost2);

lodash versions prior to 4.17.21 are vulnerable to Command Injection via the template function.