CVE-2021-3647: Urijs URIjs Vulnerable To Hostname Spoofing Vulnerability

Q: What is CVE-2021-3647?

CVE-2021-3647 is a security vulnerability in Urijs involving URIjs Vulnerable to Hostname spoofing via backslashes in URL under CWE-601: URL Redirection to Untrusted Site ('Open Redirect').

Q: Which Urijs versions are affected?

Affected versions include releases prior to 1.19.7 across affected packages: urijs.

Q: What version fixes CVE-2021-3647?

Upgrading to 1.19.7 (or the latest patched release for your respective branch) resolves the vulnerability.

Q: Is urijs affected?

Yes, urijs is affected in releases prior to 1.19.7. Upgrade your dependency to 1.19.7 or later.

Q: What is the CVSS score of CVE-2021-3647?

CVE-2021-3647 has a CVSS v3.1 base score of 5.3 (MODERATE) with vector string CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N.

Q: What CWE is associated with CVE-2021-3647?

CVE-2021-3647 is classified under CWE-601: URL Redirection to Untrusted Site ('Open Redirect') (The web application accepts a user-controlled input that specifies a link to an external site, and uses that link in a redirect.).

Q: How can I check npm dependencies for CVE-2021-3647?

Run the dependency tree command: 'npm ls urijs'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.

MODERATE

Advisory Identifier: GHSA-89gv-h8wf-cg8r

CVSS 5.3

CWE-601

Published 2021-07-19

Advisory Summary

CVE-2021-3647 is a MODERATE (CVSS 5.3) urijs vulnerable to hostname spoofing vulnerability (CWE-601: URL Redirection to Untrusted Site ('Open Redirect')) affecting Urijs libraries in the npm ecosystem. The issue involves urijs vulnerable to hostname spoofing via backslashes in url. Remediation is available by upgrading affected packages to version 1.19.7.

CVE-2021-3647 at a Glance

CVE Identifier CVE-2021-3647

GHSA Identifier GHSA-89gv-h8wf-cg8r

Severity MODERATE

CVSS v3.1 Base Score 5.3

CWE Classification CWE-601: URL Redirection to Untrusted Site ('Open Redirect')

Affected Product Urijs

Package Ecosystem npm

Published Date 2021-07-19

Last Updated 2023-09-07

Security Impact

CVSS: 5.3

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:N/S:U/C:N/I:L/A:N).

Attack Vector Network (AV:N)

Attack Complexity Low (AC:L)

Privileges Required None (PR:N)

User Interaction None (UI:N)

Scope Unchanged (S:U)

Confidentiality None (C:N)

Integrity Low (I:L)

Availability None (A:N)

How to Fix CVE-2021-3647

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

urijs fixed: 1.19.7

npm install urijs@1.19.7

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 urijs

How to Check if You Are Affected

To determine whether your Node.js application is affected by CVE-2021-3647, inspect your project dependencies using npm:

npm ls urijs

Analyze the terminal output to locate any version of Urijs in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 1.19.7), your application is affected.

Note: The npm ls urijs 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-601: URL Redirection to Untrusted Site ('Open Redirect'), where the web application accepts a user-controlled input that specifies a link to an external site, and uses that link in a redirect. In Urijs, 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

### Impact If using affected versions to determine a URL's hostname, the hostname can be spoofed by using a combination of backslash (`\`) and slash (`/`) characters as part of the scheme delimiter, e.g. `scheme:/\/\/\hostname`. If the hostname is used in security decisions, the decision may be incorrect. Depending on library usage and attacker intent, impacts may include allow/block list bypasses, SSRF attacks, open redirects, or other undesired behavior. Example URL: `https:/\/\/\expected-example.com/path` Escaped string: `https:/\\/\\/\\expected-example.com/path` (JavaScript strings must escape backslash) Affected versions incorrectly return no hostname. Patched versions correctly return `expected-example.com`. Patched versions match the behavior of other parsers which implement the [WHATWG URL specification](https://url.spec.whatwg.org/), including web browsers and [Node's built-in URL class](https://nodejs.org/api/url.html). ### Patches Version 1.19.7 is patched against all known payload variants. ### References https://github.com/medialize/URI.js/releases/tag/v1.19.7 (fix for this particular bypass) https://github.com/medialize/URI.js/releases/tag/v1.19.6 (fix for related bypass) https://github.com/medialize/URI.js/releases/tag/v1.19.4 (fix for related bypass) https://github.com/medialize/URI.js/releases/tag/v1.19.3 (fix for related bypass) [PR #233](https://github.com/medialize/URI.js/pull/233) (initial fix for backslash handling) ### For more information If you have any questions or comments about this advisory, open an issue in https://github.com/medialize/URI.js ### Reporter credit [ready-research](https://github.com/ready-research) via https://huntr.dev/

CVE-2021-3647 Affected Urijs Versions

1 component(s)

Fixed Versions:

1.19.7

Product / Package	Ecosystem	Affected Versions	Fixed Version
urijs npm/urijs	npm	< 1.19.7	1.19.7

References

GitHub Advisory / Wiki ADVISORY

https://github.com/medialize/URI.js/security/advisories/GHSA-89gv-h8wf-cg8r

NVD — CVE-2021-3647 NVD

https://nvd.nist.gov/vuln/detail/CVE-2021-3647

Urijs Source Repository REPOSITORY

https://github.com/medialize/URI.js/pull/233

Security Fix Commit FIX COMMIT

https://github.com/medialize/URI.js/commit/ac43ca8f80c042f0256fb551ea5203863dec4481

Urijs Release RELEASE

https://github.com/medialize/URI.js/releases/tag/v1.19.3

Urijs Release RELEASE

https://github.com/medialize/URI.js/releases/tag/v1.19.4

Urijs Release RELEASE

https://github.com/medialize/URI.js/releases/tag/v1.19.6

Urijs Release RELEASE

https://github.com/medialize/URI.js/releases/tag/v1.19.7

huntr.dev/bounties/1625558772... WEB

https://huntr.dev/bounties/1625558772840-medialize/URI.js

Frequently Asked Questions

What is CVE-2021-3647?

CVE-2021-3647 is a security vulnerability in Urijs involving URIjs Vulnerable to Hostname spoofing via backslashes in URL under CWE-601: URL Redirection to Untrusted Site ('Open Redirect').

Which Urijs versions are affected?

Affected versions include releases prior to 1.19.7 across affected packages: urijs.

What version fixes CVE-2021-3647?

Upgrading to 1.19.7 (or the latest patched release for your respective branch) resolves the vulnerability.

Is urijs affected?

Yes, urijs is affected in releases prior to 1.19.7. Upgrade your dependency to 1.19.7 or later.

What is the CVSS score of CVE-2021-3647?

CVE-2021-3647 has a CVSS v3.1 base score of 5.3 (MODERATE) with vector string CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N.

What CWE is associated with CVE-2021-3647?

CVE-2021-3647 is classified under CWE-601: URL Redirection to Untrusted Site ('Open Redirect') (The web application accepts a user-controlled input that specifies a link to an external site, and uses that link in a redirect.).

How can I check npm dependencies for CVE-2021-3647?

Run the dependency tree command: 'npm ls urijs'. 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-89gv-h8wf-cg8r",
  "modified" : "2023-09-07T20:18:00Z",
  "published" : "2021-07-19T21:22:36Z",
  "aliases" : [ "CVE-2021-3647" ],
  "summary" : "URIjs Vulnerable to Hostname spoofing via backslashes in URL ",
  "details" : "### Impact\nIf using affected versions to determine a URL's hostname, the hostname can be spoofed by using a combination of backslash (`\\`) and slash (`/`) characters as part of the scheme delimiter, e.g. `scheme:/\\/\\/\\hostname`. If the hostname is used in security decisions, the decision may be incorrect.\n\nDepending on library usage and attacker intent, impacts may include allow/block list bypasses, SSRF attacks, open redirects, or other undesired behavior.\n\nExample URL: `https:/\\/\\/\\expected-example.com/path`\nEscaped string: `https:/\\\\/\\\\/\\\\expected-example.com/path` (JavaScript strings must escape backslash)\n\nAffected versions incorrectly return no hostname. Patched versions correctly return `expected-example.com`. Patched versions match the behavior of other parsers which implement the [WHATWG URL specification](https://url.spec.whatwg.org/), including web browsers and [Node's built-in URL class](https://nodejs.org/api/url.html).\n\n### Patches\nVersion 1.19.7 is patched against all known payload variants.\n\n### References\nhttps://github.com/medialize/URI.js/releases/tag/v1.19.7 (fix for this particular bypass)\nhttps://github.com/medialize/URI.js/releases/tag/v1.19.6 (fix for related bypass)\nhttps://github.com/medialize/URI.js/releases/tag/v1.19.4 (fix for related bypass)\nhttps://github.com/medialize/URI.js/releases/tag/v1.19.3 (fix for related bypass)\n[PR #233](https://github.com/medialize/URI.js/pull/233) (initial fix for backslash handling)\n\n### For more information\nIf you have any questions or comments about this advisory, open an issue in https://github.com/medialize/URI.js\n\n### Reporter credit\n[ready-research](https://github.com/ready-research) via https://huntr.dev/",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "npm",
      "name" : "urijs"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "1.19.7"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/medialize/URI.js/security/advisories/GHSA-89gv-h8wf-cg8r"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2021-3647"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/medialize/URI.js/pull/233"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/medialize/URI.js/commit/ac43ca8f80c042f0256fb551ea5203863dec4481"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/medialize/URI.js/releases/tag/v1.19.3"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/medialize/URI.js/releases/tag/v1.19.4"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/medialize/URI.js/releases/tag/v1.19.6"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/medialize/URI.js/releases/tag/v1.19.7"
  }, {
    "type" : "WEB",
    "url" : "https://huntr.dev/bounties/1625558772840-medialize/URI.js"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-601" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2021-07-19T16:38:54Z",
    "nvd_published_at" : "2021-07-16T11:15:00Z"
  }
}

CVSS V3

5.3 MODERATE

Attack Vector Network (AV:N)

Attack Complexity Low (AC:L)

Privileges Required None (PR:N)

User Interaction None (UI:N)

Scope Unchanged (S:U)

Confidentiality None (C:N)

Integrity Low (I:L)

Availability None (A:N)

Vector String

CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N

Advisory Metadata

Source ID: GHSA-89gv-h8wf-cg8r
Schema Version: 1.4.0
Published: 2021-07-19 21:22
Last Modified: 2023-09-07 20:18
Database Record File: advisories/github-reviewed/2021/07/GHSA-89gv-h8wf-cg8r/GHSA-89gv-h8wf-cg8r.json