CVE-2016-10547: Nunjucks Cross-Site Scripting Vulnerability

MODERATE
Advisory Identifier: GHSA-f7ph-p5rv-phw2
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CWE-79
Published
Advisory Summary

CVE-2016-10547 is a MODERATE cross-site scripting vulnerability (CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')) affecting Nunjucks libraries in the npm ecosystem. The issue involves cross-site scripting in nunjucks. Remediation is available by upgrading affected packages to version 2.4.3.

CVE-2016-10547 at a Glance

CVE Identifier CVE-2016-10547
GHSA Identifier GHSA-f7ph-p5rv-phw2
Severity MODERATE
CVSS v3.1 Base Score N/A
CWE Classification CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
Affected Product Nunjucks
Package Ecosystem npm
Published Date
Last Updated

How to Fix CVE-2016-10547

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

nunjucks fixed: 2.4.3 
npm install nunjucks@2.4.3
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 nunjucks

How to Check if You Are Affected

To determine whether your Node.js application is affected by CVE-2016-10547, inspect your project dependencies using npm:

npm ls nunjucks

Analyze the terminal output to locate any version of Nunjucks in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 2.4.3), your application is affected.

Note: The npm ls nunjucks 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-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting'), where the product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users. In Nunjucks, 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

Affected versions of `nunjucks` do not properly escape specially structured user input in template vars when in auto-escape mode, resulting in a cross-site scripting vulnerability. ## Proof of Concept By using an array for the keys in a template var, escaping is bypassed. ```javascript name[]=<script>alert(1)</script> ``` A full PoC is available in the references section. ## Recommendation Update to version 2.4.3 or later.

CVE-2016-10547 Affected Nunjucks Versions

1 component(s)
Fixed Versions:
2.4.3
Product / Package Ecosystem Affected Versions Fixed Version
nunjucks
npm/nunjucks
npm
< 2.4.3
2.4.3

References

NVD — CVE-2016-10547 NVD
https://nvd.nist.gov/vuln/detail/CVE-2016-10547
Nunjucks Source Repository REPOSITORY
https://github.com/mozilla/nunjucks/issues/835
GitHub Advisory / Wiki ADVISORY
https://github.com/advisories/GHSA-f7ph-p5rv-phw2
Nunjucks Source Repository REPOSITORY
https://github.com/matt-/nunjucks_test
www.npmjs.com/advisories/147 WEB
https://www.npmjs.com/advisories/147

Frequently Asked Questions

What is CVE-2016-10547?
CVE-2016-10547 is a security vulnerability in Nunjucks involving Cross-Site Scripting in nunjucks under CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting').
Which Nunjucks versions are affected?
Affected versions include releases prior to 2.4.3 across affected packages: nunjucks.
What version fixes CVE-2016-10547?
Upgrading to 2.4.3 (or the latest patched release for your respective branch) resolves the vulnerability.
Is nunjucks affected?
Yes, nunjucks is affected in releases prior to 2.4.3. Upgrade your dependency to 2.4.3 or later.
What CWE is associated with CVE-2016-10547?
CVE-2016-10547 is classified under CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') (The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users.).
How can I check npm dependencies for CVE-2016-10547?
Run the dependency tree command: 'npm ls nunjucks'. 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
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-f7ph-p5rv-phw2",
  "modified" : "2020-08-31T18:12:27Z",
  "published" : "2018-11-06T23:13:37Z",
  "aliases" : [ "CVE-2016-10547" ],
  "summary" : "Cross-Site Scripting in nunjucks",
  "details" : "Affected versions of `nunjucks` do not properly escape specially structured user input in template vars when in auto-escape mode, resulting in a cross-site scripting vulnerability.\n\n## Proof of Concept\n\nBy using an array for the keys in a template var, escaping is bypassed.\n```javascript\nname[]=<script>alert(1)</script>\n```\n\nA full PoC is available in the references section.\n\n\n## Recommendation\n\nUpdate to version 2.4.3 or later.",
  "severity" : [ ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "npm",
      "name" : "nunjucks"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "2.4.3"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2016-10547"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/mozilla/nunjucks/issues/835"
  }, {
    "type" : "ADVISORY",
    "url" : "https://github.com/advisories/GHSA-f7ph-p5rv-phw2"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/matt-/nunjucks_test"
  }, {
    "type" : "WEB",
    "url" : "https://www.npmjs.com/advisories/147"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-79" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2020-06-16T21:34:04Z",
    "nvd_published_at" : null
  }
}