CVE-2019-14537: Yourls/yourls Remote Code Execution Vulnerability

CRITICAL
Advisory Identifier: GHSA-vf23-f26f-mjj9
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CVSS 9.8
CWE-843
Published
Advisory Summary

CVE-2019-14537 is a CRITICAL (CVSS 9.8) remote code execution vulnerability (CWE-843: Access of Resource Using Incompatible Type ('Type Confusion')) affecting Yourls/yourls libraries in the Packagist ecosystem. The issue involves access of resource using incompatible type ('type confusion') in yourls/yourls. Remediation is available by upgrading affected packages to version 1.7.4.

CVE-2019-14537 at a Glance

CVE Identifier CVE-2019-14537
GHSA Identifier GHSA-vf23-f26f-mjj9
Severity CRITICAL
CVSS v3.1 Base Score 9.8
CWE Classification CWE-843: Access of Resource Using Incompatible Type ('Type Confusion')
Affected Product Yourls/yourls
Package Ecosystem Packagist
Published Date
Last Updated

Security Impact

CVSS: 9.8

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:H/I:H/A:H).

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 High (C:H)
Integrity High (I:H)
Availability High (A:H)

How to Fix CVE-2019-14537

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

yourls/yourls fixed: 1.7.4 
Upgrade yourls/yourls to 1.7.4
Verify Direct and Transitive Dependencies

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

inspect dependencies for yourls/yourls

How to Check if You Are Affected

To determine whether your application is affected by CVE-2019-14537, inspect your project dependencies for Yourls/yourls:

inspect dependencies for yourls/yourls

Analyze the terminal output to locate any version of Yourls/yourls in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 1.7.4), your application is affected.

Note: Verify declared build manifests and deployed runtime container environments.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-843: Access of Resource Using Incompatible Type ('Type Confusion'), where the product allocates or initializes a resource such as a pointer, object, or variable using one type, but it later accesses that resource using a type that is incompatible with the original type. In Yourls/yourls, 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 YOURLS through 1.7.3 is affected by a type juggling vulnerability in the API component that can result in login bypass. ### Patches https://github.com/YOURLS/YOURLS/releases/tag/1.7.4 https://github.com/YOURLS/YOURLS/pull/2542 ### References * https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2019-14537 * https://github.com/Wocanilo/CVE-2019-14537 ### For more information If you have any questions or comments about this advisory: * Open an issue in [YOURLS repository](https://github.com/YOURLS/YOURLS)

CVE-2019-14537 Affected Yourls/yourls Versions

1 component(s)
Fixed Versions:
1.7.4
Product / Package Ecosystem Affected Versions Fixed Version
yourls/yourls
 Packagist
< 1.7.4
1.7.4

References

GitHub Advisory / Wiki ADVISORY
https://github.com/YOURLS/YOURLS/security/advisories/GHSA-vf23-f26f-mjj9
NVD — CVE-2019-14537 NVD
https://nvd.nist.gov/vuln/detail/CVE-2019-14537
Yourls/yourls Source Repository REPOSITORY
https://github.com/YOURLS/YOURLS/pull/2542
Yourls/yourls Source Repository REPOSITORY
https://github.com/Wocanilo/CVE-2019-14537
Yourls/yourls Source Repository REPOSITORY
https://github.com/YOURLS/YOURLS
Yourls/yourls Source Repository REPOSITORY
https://github.com/YOURLS/YOURLS/commits/master
Yourls/yourls Source Repository REPOSITORY
https://github.com/YOURLS/YOURLS/releases
GitHub Advisory / Wiki ADVISORY
https://github.com/advisories/GHSA-vf23-f26f-mjj9
Yourls/yourls Security Information SECURITY
https://security-garage.com/index.php/cves/cve-2019-14537-api-authentication-bypass-via-type-juggling

Frequently Asked Questions

What is CVE-2019-14537?
CVE-2019-14537 is a security vulnerability in Yourls/yourls involving Access of Resource Using Incompatible Type ('Type Confusion') in yourls/yourls under CWE-843: Access of Resource Using Incompatible Type ('Type Confusion').
Which Yourls/yourls versions are affected?
Affected versions include releases prior to 1.7.4 across affected packages: yourls/yourls.
What version fixes CVE-2019-14537?
Upgrading to 1.7.4 (or the latest patched release for your respective branch) resolves the vulnerability.
Is yourls/yourls affected?
Yes, yourls/yourls is affected in releases prior to 1.7.4. Upgrade your dependency to 1.7.4 or later.
What is the CVSS score of CVE-2019-14537?
CVE-2019-14537 has a CVSS v3.1 base score of 9.8 (CRITICAL) with vector string CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.
What CWE is associated with CVE-2019-14537?
CVE-2019-14537 is classified under CWE-843: Access of Resource Using Incompatible Type ('Type Confusion') (The product allocates or initializes a resource such as a pointer, object, or variable using one type, but it later accesses that resource using a type that is incompatible with the original type.).
How can I check Packagist dependencies for CVE-2019-14537?
Run the dependency tree command: 'inspect dependencies for yourls/yourls'. 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-vf23-f26f-mjj9",
  "modified" : "2026-06-08T23:15:01Z",
  "published" : "2019-09-23T18:32:02Z",
  "aliases" : [ "CVE-2019-14537" ],
  "summary" : "Access of Resource Using Incompatible Type ('Type Confusion')  in yourls/yourls",
  "details" : "### Impact\nYOURLS through 1.7.3 is affected by a type juggling vulnerability in the API component that can result in login bypass.\n\n### Patches\nhttps://github.com/YOURLS/YOURLS/releases/tag/1.7.4\nhttps://github.com/YOURLS/YOURLS/pull/2542\n\n### References\n* https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2019-14537\n* https://github.com/Wocanilo/CVE-2019-14537\n\n### For more information\nIf you have any questions or comments about this advisory:\n* Open an issue in [YOURLS repository](https://github.com/YOURLS/YOURLS)",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Packagist",
      "name" : "yourls/yourls"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "1.7.4"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/YOURLS/YOURLS/security/advisories/GHSA-vf23-f26f-mjj9"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2019-14537"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/YOURLS/YOURLS/pull/2542"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/Wocanilo/CVE-2019-14537"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/YOURLS/YOURLS"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/YOURLS/YOURLS/commits/master"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/YOURLS/YOURLS/releases"
  }, {
    "type" : "ADVISORY",
    "url" : "https://github.com/advisories/GHSA-vf23-f26f-mjj9"
  }, {
    "type" : "WEB",
    "url" : "https://security-garage.com/index.php/cves/cve-2019-14537-api-authentication-bypass-via-type-juggling"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-843" ],
    "severity" : "CRITICAL",
    "github_reviewed" : true,
    "github_reviewed_at" : "2020-06-16T21:57:30Z",
    "nvd_published_at" : null
  }
}