CVE-2022-21169: Express xss sanitizer Cross-Site Scripting Vulnerability

MODERATE
Advisory Identifier: GHSA-grjp-4jmr-mjcw
Share
CVSS 6.1
CWE-1321
Published
Advisory Summary

CVE-2022-21169 is a MODERATE (CVSS 6.1) cross-site scripting vulnerability (CWE-1321: Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution')) affecting Express xss sanitizer libraries in the npm ecosystem. The issue involves express-xss-sanitizer vulnerable to prototype pollution via allowedtags attribute. Remediation is available by upgrading affected packages to version 1.1.3.

CVE-2022-21169 at a Glance

CVE Identifier CVE-2022-21169
GHSA Identifier GHSA-grjp-4jmr-mjcw
Severity MODERATE
CVSS v3.1 Base Score 6.1
CWE Classification CWE-1321: Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution')
Affected Product Express xss sanitizer
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:3.1/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-2022-21169

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

express-xss-sanitizer fixed: 1.1.3 
npm install express-xss-sanitizer@1.1.3
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 express-xss-sanitizer

How to Check if You Are Affected

To determine whether your Node.js application is affected by CVE-2022-21169, inspect your project dependencies using npm:

npm ls express-xss-sanitizer

Analyze the terminal output to locate any version of Express xss sanitizer in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 1.1.3), your application is affected.

Note: The npm ls express-xss-sanitizer 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-1321: Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution'), where the product receives input from an upstream component that specifies attributes that are to be initialized or updated in an object, but it does not properly control modifications of attributes of the object prototype. In Express xss sanitizer, 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

The package express-xss-sanitizer before 1.1.3 is vulnerable to Prototype Pollution via the `allowedTags` attribute, allowing the attacker to bypass xss sanitization.

CVE-2022-21169 Affected Express xss sanitizer Versions

1 component(s)
Fixed Versions:
1.1.3
Product / Package Ecosystem Affected Versions Fixed Version
express-xss-sanitizer
npm/express-xss-sanitizer
npm
< 1.1.3
1.1.3

References

Security Fix Commit FIX COMMIT
https://github.com/AhmedAdelFahim/express-xss-sanitizer/commit/3bf8aaaf4dbb1c209dcb8d87a82711a54c1ab39a
runkit.com/embed/w306l6zfm7tu WEB
https://runkit.com/embed/w306l6zfm7tu
Express xss sanitizer Security Information SECURITY
https://security.snyk.io/vuln/SNYK-JS-EXPRESSXSSSANITIZER-3027443
NVD — CVE-2022-21169 NVD
https://nvd.nist.gov/vuln/detail/CVE-2022-21169
Express xss sanitizer Source Repository REPOSITORY
https://github.com/AhmedAdelFahim/express-xss-sanitizer/issues/4
Express xss sanitizer Source Repository REPOSITORY
https://github.com/AhmedAdelFahim/express-xss-sanitizer

Frequently Asked Questions

What is CVE-2022-21169?
CVE-2022-21169 is a security vulnerability in Express xss sanitizer involving express-xss-sanitizer vulnerable to Prototype Pollution via allowedTags attribute under CWE-1321: Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution').
Which Express xss sanitizer versions are affected?
Affected versions include releases prior to 1.1.3 across affected packages: express-xss-sanitizer.
What version fixes CVE-2022-21169?
Upgrading to 1.1.3 (or the latest patched release for your respective branch) resolves the vulnerability.
Is express-xss-sanitizer affected?
Yes, express-xss-sanitizer is affected in releases prior to 1.1.3. Upgrade your dependency to 1.1.3 or later.
What is the CVSS score of CVE-2022-21169?
CVE-2022-21169 has a CVSS v3.1 base score of 6.1 (MODERATE) with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N.
What CWE is associated with CVE-2022-21169?
CVE-2022-21169 is classified under CWE-1321: Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution') (The product receives input from an upstream component that specifies attributes that are to be initialized or updated in an object, but it does not properly control modifications of attributes of the object prototype.).
How can I check npm dependencies for CVE-2022-21169?
Run the dependency tree command: 'npm ls express-xss-sanitizer'. 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-grjp-4jmr-mjcw",
  "modified" : "2022-09-30T04:42:55Z",
  "published" : "2022-09-27T00:00:22Z",
  "aliases" : [ "CVE-2022-21169" ],
  "summary" : "express-xss-sanitizer vulnerable to Prototype Pollution via allowedTags attribute",
  "details" : "The package express-xss-sanitizer before 1.1.3 is vulnerable to Prototype Pollution via the `allowedTags` attribute, allowing the attacker to bypass xss sanitization.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "npm",
      "name" : "express-xss-sanitizer"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "1.1.3"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2022-21169"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/AhmedAdelFahim/express-xss-sanitizer/issues/4"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/AhmedAdelFahim/express-xss-sanitizer/commit/3bf8aaaf4dbb1c209dcb8d87a82711a54c1ab39a"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/AhmedAdelFahim/express-xss-sanitizer"
  }, {
    "type" : "WEB",
    "url" : "https://runkit.com/embed/w306l6zfm7tu"
  }, {
    "type" : "WEB",
    "url" : "https://security.snyk.io/vuln/SNYK-JS-EXPRESSXSSSANITIZER-3027443"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-1321" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2022-09-30T04:42:55Z",
    "nvd_published_at" : "2022-09-26T05:15:00Z"
  }
}