CVE-2019-16776: Npm Npm Symlink Reference Outside Of Vulnerability

HIGH
Advisory Identifier: GHSA-x8qc-rrcw-4r46
CVSS 7.7
CWE-22
Published
Advisory Summary

CVE-2019-16776 is a HIGH (CVSS 7.7) npm symlink reference outside of vulnerability (CWE-22: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')) affecting Npm libraries in the npm ecosystem. The issue involves npm symlink reference outside of node_modules. Remediation is available by upgrading affected packages to version 6.13.3.

CVE-2019-16776 at a Glance

CVE Identifier CVE-2019-16776
GHSA Identifier GHSA-x8qc-rrcw-4r46
Severity HIGH
CVSS v3.1 Base Score 7.7
CWE Classification CWE-22: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
Affected Product Npm
Package Ecosystem npm
Published Date
Last Updated

Security Impact

CVSS: 7.7

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:C/C:H/I:H/A:N).

Attack Vector Network (AV:N)
Attack Complexity High (AC:H)
Privileges Required Low (PR:L)
User Interaction Required (UI:R)
Scope Changed (S:C)
Confidentiality High (C:H)
Integrity High (I:H)
Availability None (A:N)

How to Fix CVE-2019-16776

To remediate this vulnerability, upgrade all affected Npm dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

npm fixed: 6.13.3
npm install npm@6.13.3
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release:

npm ls npm

How to Check if You Are Affected

To determine whether your Node.js application is affected by CVE-2019-16776, inspect your project dependencies using npm:

npm ls npm

Analyze the terminal output to locate any version of Npm in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 6.13.3), your application is affected.

Note: The npm ls npm command inspects dependencies declared in your package.json and lockfile; it does not perform automated runtime dynamic scanning.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-22: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal'), where the product uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the product does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory. In Npm, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

Versions of the npm CLI prior to 6.13.3 are vulnerable to a symlink reference outside of node_modules. It is possible for packages to create symlinks to files outside of the`node_modules` folder through the `bin` field upon installation. A properly constructed entry in the package.json bin field would allow a package publisher to create a symlink pointing to arbitrary files on a user’s system when the package is installed. Only files accessible by the user running the `npm install` are affected. This behavior is still possible through install scripts. This vulnerability bypasses a user using the --ignore-scripts install option. ## Recommendation Upgrade to version 6.13.3 or later.

CVE-2019-16776 Affected Npm Versions

1 component(s)
Fixed Versions:
6.13.3
Product / Package Ecosystem Affected Versions Fixed Version
npm
npm
< 6.13.3
6.13.3

References

Frequently Asked Questions

What is CVE-2019-16776?
CVE-2019-16776 is a security vulnerability in Npm involving npm symlink reference outside of node_modules under CWE-22: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal').
Which Npm versions are affected?
Affected versions include releases prior to 6.13.3 across affected packages: npm.
What version fixes CVE-2019-16776?
Upgrading to 6.13.3 (or the latest patched release for your respective branch) resolves the vulnerability.
Is npm affected?
Yes, npm is affected in releases prior to 6.13.3. Upgrade your dependency to 6.13.3 or later.
What is the CVSS score of CVE-2019-16776?
CVE-2019-16776 has a CVSS v3.1 base score of 7.7 (HIGH) with vector string CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:C/C:H/I:H/A:N.
What CWE is associated with CVE-2019-16776?
CVE-2019-16776 is classified under CWE-22: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal') (The product uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the product does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory.).
How can I check npm dependencies for CVE-2019-16776?
Run the dependency tree command: 'npm ls npm'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-x8qc-rrcw-4r46",
  "modified" : "2022-08-10T23:58:46Z",
  "published" : "2019-12-13T15:39:26Z",
  "aliases" : [ "CVE-2019-16776" ],
  "summary" : "npm symlink reference outside of node_modules",
  "details" : "Versions of the npm CLI prior to 6.13.3 are vulnerable to a symlink reference outside of node_modules. It is possible for packages to create symlinks to files outside of the`node_modules` folder through the `bin` field upon installation. A properly constructed entry in the package.json bin field would allow a package publisher to create a symlink pointing to arbitrary files on a user’s system when the package is installed. Only files accessible by the user running the `npm install` are affected.  \n\nThis behavior is still possible through install scripts. This vulnerability bypasses a user using the --ignore-scripts install option.\n\n\n## Recommendation\n\nUpgrade to version 6.13.3 or later.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:C/C:H/I:H/A:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "npm",
      "name" : "npm"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "6.13.3"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/npm/cli/security/advisories/GHSA-x8qc-rrcw-4r46"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2019-16776"
  }, {
    "type" : "WEB",
    "url" : "https://access.redhat.com/errata/RHEA-2020:0330"
  }, {
    "type" : "WEB",
    "url" : "https://access.redhat.com/errata/RHSA-2020:0573"
  }, {
    "type" : "WEB",
    "url" : "https://access.redhat.com/errata/RHSA-2020:0579"
  }, {
    "type" : "WEB",
    "url" : "https://access.redhat.com/errata/RHSA-2020:0597"
  }, {
    "type" : "WEB",
    "url" : "https://access.redhat.com/errata/RHSA-2020:0602"
  }, {
    "type" : "WEB",
    "url" : "https://blog.npmjs.org/post/189618601100/binary-planting-with-the-npm-cli"
  }, {
    "type" : "ADVISORY",
    "url" : "https://github.com/advisories/GHSA-x8qc-rrcw-4r46"
  }, {
    "type" : "WEB",
    "url" : "https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/Z36UKPO5F3PQ3Q2POMF5LEKXWAH5RUFP"
  }, {
    "type" : "WEB",
    "url" : "https://www.npmjs.com/advisories/1436"
  }, {
    "type" : "WEB",
    "url" : "https://www.oracle.com/security-alerts/cpujan2020.html"
  }, {
    "type" : "WEB",
    "url" : "http://lists.opensuse.org/opensuse-security-announce/2020-01/msg00027.html"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-22" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2020-06-16T22:02:49Z",
    "nvd_published_at" : "2019-12-13T01:15:00Z"
  }
}