CVE-2024-38537: Ethyca fides Inclusion Of Untrusted Polyfill.io Code Vulnerability

LOW
Advisory Identifier: GHSA-cvw4-c69g-7v7m
CVSS 0.0
CWE-829
Published
Advisory Summary

CVE-2024-38537 is a LOW (CVSS 0.0) inclusion of untrusted polyfill.io code vulnerability (CWE-829: Inclusion of Functionality from Untrusted Control Sphere) affecting Ethyca fides libraries in the PyPI ecosystem. The issue involves inclusion of untrusted polyfill.io code vulnerability in fides.js. Remediation is available by upgrading affected packages to version 2.39.1.

CVE-2024-38537 at a Glance

CVE Identifier CVE-2024-38537
GHSA Identifier GHSA-cvw4-c69g-7v7m
Severity LOW
CVSS v3.1 Base Score 0.0
CWE Classification CWE-829: Inclusion of Functionality from Untrusted Control Sphere
Affected Product Ethyca fides
Package Ecosystem PyPI
Published Date
Last Updated

Security Impact

CVSS: 0.0

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:N/S:U/C:N/I:N/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 None (I:N)
Availability None (A:N)

How to Fix CVE-2024-38537

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

ethyca-fides fixed: 2.39.1
pip install ethyca-fides>=2.39.1
Verify Direct and Transitive Dependencies

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

pip show ethyca-fides

How to Check if You Are Affected

To determine whether your Python environment is affected by CVE-2024-38537, inspect your installed packages using pip:

pip show ethyca-fides

Analyze the terminal output to locate any version of Ethyca fides in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 2.39.1), your application is affected.

Note: The pip show ethyca-fides command checks currently installed packages in your active Python environment.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-829: Inclusion of Functionality from Untrusted Control Sphere, where the product imports, requires, or includes executable functionality (such as a library) from a source that is outside of the intended control sphere. In Ethyca fides, 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

### Note On Thursday, June 27, 2024, Cloudflare and Namecheap intervened at a domain level to ensure `polyfill.io` and its subdomains could not resolve to the compromised service, rendering this vulnerability **unexploitable**. The following sections describe this vulnerability prior to the domain level intervention, when it was still exploitable. ### Impact `fides.js`, a client-side script used to interact with the consent management features of Fides, used the `polyfill.io` domain in a very limited edge case, when it detected a legacy browser such as IE11 that did not support the fetch standard. On June 25th, 2024, Sansec published the following regarding the `polyfill.io` domain. > The polyfill.js is a popular open source library to support older browsers. 100K+ sites embed it using the cdn.polyfill.io domain... However, in February this year, a Chinese company bought the domain and the Github account. Since then, this domain was caught injecting malware on mobile devices via any site that embeds cdn.polyfill.io. Therefore it was possible for users of legacy, pre-2017 browsers who navigate to a page serving `fides.js` to download and execute malicious scripts from the compromised domain. No exploitation of `fides.js` via `polyfill.io` has been identified at this time, but other script developers who use `https://cdn.polyfill.io/v2/polyfill.min.js` have reported redirects to malicious websites. ### Patches The vulnerability has been patched in Fides version `2.39.1`. Users are advised to upgrade to this version or later to secure their systems against this threat. ### Workarounds Prior to the domain level intervention, there were no server-side workarounds and the confidentiality, integrity, and availability impacts of this vulnerability were high. Clients could ensure they were not affected by using a modern browser that supported the fetch standard. caniuse.com/fetch estimates that 97.52% of browser users use a browser that supports the fetch standard. ### References - https://sansec.io/research/polyfill-supply-chain-attack - https://github.com/ethyca/fides/pull/5026/ - https://fetch.spec.whatwg.org/

CVE-2024-38537 Affected Ethyca fides Versions

1 component(s)
Fixed Versions:
2.39.1
Product / Package Ecosystem Affected Versions Fixed Version
ethyca-fides
PyPI
< 2.39.1
2.39.1

References

Frequently Asked Questions

What is CVE-2024-38537?
CVE-2024-38537 is a security vulnerability in Ethyca fides involving Inclusion of Untrusted polyfill.io Code Vulnerability in fides.js under CWE-829: Inclusion of Functionality from Untrusted Control Sphere.
Which Ethyca fides versions are affected?
Affected versions include releases prior to 2.39.1 across affected packages: ethyca-fides.
What version fixes CVE-2024-38537?
Upgrading to 2.39.1 (or the latest patched release for your respective branch) resolves the vulnerability.
Is ethyca-fides affected?
Yes, ethyca-fides is affected in releases prior to 2.39.1. Upgrade your dependency to 2.39.1 or later.
What is the CVSS score of CVE-2024-38537?
CVE-2024-38537 has a CVSS v3.1 base score of 0.0 (LOW) with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:N.
What CWE is associated with CVE-2024-38537?
CVE-2024-38537 is classified under CWE-829: Inclusion of Functionality from Untrusted Control Sphere (The product imports, requires, or includes executable functionality (such as a library) from a source that is outside of the intended control sphere.).
How can I check PyPI dependencies for CVE-2024-38537?
Run the dependency tree command: 'pip show ethyca-fides'. 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-cvw4-c69g-7v7m",
  "modified" : "2024-07-05T21:27:24Z",
  "published" : "2024-07-02T21:20:07Z",
  "aliases" : [ "CVE-2024-38537" ],
  "summary" : "Inclusion of Untrusted polyfill.io Code Vulnerability in fides.js",
  "details" : "### Note\n\nOn Thursday, June 27, 2024, Cloudflare and Namecheap intervened at a domain level to ensure `polyfill.io` and its subdomains could not resolve to the compromised service, rendering this vulnerability **unexploitable**.\n\nThe following sections describe this vulnerability prior to the domain level intervention, when it was still exploitable.\n\n### Impact\n\n`fides.js`, a client-side script used to interact with the consent management features of Fides, used the `polyfill.io` domain in a very limited edge case, when it detected a legacy browser such as IE11 that did not support the fetch standard.\n\nOn June 25th, 2024, Sansec published the following regarding the `polyfill.io` domain.\n\n> The polyfill.js is a popular open source library to support older browsers. 100K+ sites embed it using the cdn.polyfill.io domain... However, in February this year, a Chinese company bought the domain and the Github account. Since then, this domain was caught injecting malware on mobile devices via any site that embeds cdn.polyfill.io.\n\nTherefore it was possible for users of legacy, pre-2017 browsers who navigate to a page serving `fides.js` to download and execute malicious scripts from the compromised domain.\n\nNo exploitation of `fides.js` via `polyfill.io` has been identified at this time, but other script developers who use `https://cdn.polyfill.io/v2/polyfill.min.js` have reported redirects to malicious websites.\n\n### Patches\nThe vulnerability has been patched in Fides version `2.39.1`. Users are advised to upgrade to this version or later to secure their systems against this threat.\n\n### Workarounds\n\nPrior to the domain level intervention, there were no server-side workarounds and the confidentiality, integrity, and availability impacts of this vulnerability were high. \n\nClients could ensure they were not affected by using a modern browser that supported the fetch standard. caniuse.com/fetch estimates that 97.52% of browser users use a browser that supports the fetch standard.\n\n### References\n- https://sansec.io/research/polyfill-supply-chain-attack\n- https://github.com/ethyca/fides/pull/5026/\n- https://fetch.spec.whatwg.org/",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "PyPI",
      "name" : "ethyca-fides"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "2.39.1"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/ethyca/fides/security/advisories/GHSA-cvw4-c69g-7v7m"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2024-38537"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/ethyca/fides/pull/5026"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/ethyca/fides/commit/868c4d629760572192bd61db34f5a4458ed12005"
  }, {
    "type" : "WEB",
    "url" : "https://fetch.spec.whatwg.org"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/ethyca/fides"
  }, {
    "type" : "WEB",
    "url" : "https://sansec.io/research/polyfill-supply-chain-attack"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-829" ],
    "severity" : "LOW",
    "github_reviewed" : true,
    "github_reviewed_at" : "2024-07-02T21:20:07Z",
    "nvd_published_at" : "2024-07-02T20:15:05Z"
  }
}