CVE-2015-8862: Mustache Cross-Site Scripting Vulnerability

HIGH
Advisory Identifier: GHSA-w3w8-37jv-2c58
CVSS 6.1
CWE-79
Published
Advisory Summary

CVE-2015-8862 is a HIGH (CVSS 6.1) cross-site scripting vulnerability (CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')) affecting Mustache libraries in the npm ecosystem. The issue involves cross-site scripting in mustache. Remediation is available by upgrading affected packages to version 2.2.1.

CVE-2015-8862 at a Glance

CVE Identifier CVE-2015-8862
GHSA Identifier GHSA-w3w8-37jv-2c58
Severity HIGH
CVSS v3.1 Base Score 6.1
CWE Classification CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
Affected Product Mustache
Package Ecosystem npm
Published Date
Last Updated

Security Impact

CVSS: 6.1

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N).

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

How to Fix CVE-2015-8862

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

mustache fixed: 2.2.1
npm install mustache@2.2.1
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 mustache

How to Check if You Are Affected

To determine whether your Node.js application is affected by CVE-2015-8862, inspect your project dependencies using npm:

npm ls mustache

Analyze the terminal output to locate any version of Mustache in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 2.2.1), your application is affected.

Note: The npm ls mustache 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 Mustache, 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 `mustache` prior to 2.2.1 are affected by a cross-site scripting vulnerability when attributes in mustache templates are not quoted. ### Example Template: ```<a href={{foo}}/>``` Input: ```{ 'foo' : 'test.com onload=alert(1)'}``` Rendered result: ```<a href=test.com onload=alert(1)/>``` ## Recommendation Update to version 2.2.1 or later. Alternatively, ensure that all attributes in hmustache templates are encapsulated with quotes.

CVE-2015-8862 Affected Mustache Versions

1 component(s)
Fixed Versions:
2.2.1
Product / Package Ecosystem Affected Versions Fixed Version
mustache
npm
< 2.2.1
2.2.1

References

Frequently Asked Questions

What is CVE-2015-8862?
CVE-2015-8862 is a security vulnerability in Mustache involving Cross-Site Scripting in mustache under CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting').
Which Mustache versions are affected?
Affected versions include releases prior to 2.2.1 across affected packages: mustache.
What version fixes CVE-2015-8862?
Upgrading to 2.2.1 (or the latest patched release for your respective branch) resolves the vulnerability.
Is mustache affected?
Yes, mustache is affected in releases prior to 2.2.1. Upgrade your dependency to 2.2.1 or later.
What is the CVSS score of CVE-2015-8862?
CVE-2015-8862 has a CVSS v3.1 base score of 6.1 (HIGH) with vector string CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N.
What CWE is associated with CVE-2015-8862?
CVE-2015-8862 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-2015-8862?
Run the dependency tree command: 'npm ls mustache'. 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-w3w8-37jv-2c58",
  "modified" : "2021-09-20T22:34:08Z",
  "published" : "2017-10-24T18:33:36Z",
  "aliases" : [ "CVE-2015-8862" ],
  "summary" : "Cross-Site Scripting in mustache",
  "details" : "Versions of `mustache` prior to 2.2.1 are affected by a cross-site scripting vulnerability when attributes in mustache templates are not quoted.\n\n\n\n### Example\nTemplate:\n```<a href={{foo}}/>```\n\nInput:\n```{ 'foo' : 'test.com onload=alert(1)'}```\n\nRendered result:\n```<a href=test.com onload=alert(1)/>```\n\n\n## Recommendation\n\nUpdate to version 2.2.1 or later.\nAlternatively, ensure that all attributes in hmustache templates are encapsulated with quotes.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "npm",
      "name" : "mustache"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "2.2.1"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2015-8862"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/janl/mustache.js/commit/378bcca8a5cfe4058f294a3dbb78e8755e8e0da5"
  }, {
    "type" : "ADVISORY",
    "url" : "https://github.com/advisories/GHSA-w3w8-37jv-2c58"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/janl/mustache.js"
  }, {
    "type" : "WEB",
    "url" : "https://www.npmjs.com/advisories/62"
  }, {
    "type" : "WEB",
    "url" : "https://www.tenable.com/security/tns-2016-18"
  }, {
    "type" : "WEB",
    "url" : "http://www.openwall.com/lists/oss-security/2016/04/20/11"
  }, {
    "type" : "WEB",
    "url" : "http://www.securityfocus.com/bid/96436"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-79" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2020-06-16T21:59:24Z",
    "nvd_published_at" : null
  }
}