CVE-2024-38537

Home/CVE/Fides is an open-source privacy engineering platform. `fides.js`, a client-side script used to interact with the consent

CVE

Fides is an open-source privacy engineering platform. `fides.js`, a client-side script used to interact with the consent

Fides is an open-source privacy engineering platform. 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. 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 polyfill.io domain when the domain was compromised and serving malware. No exploitation of fides.js via polyfill.io has been identified as of time of publication.

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. 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.

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.

NONE EPSS 0.22233

Schedule remediation

EPSS ≥ 0.10 - elevated exploitation probability
EPSS percentile: top 4% of all CVEs by exploitation likelihood
Public exploit or PoC is available

Sigma rules0 YARA rules0

Look this up elsewhere - one-click external pivots

NVD CVE.org CISA Vulners Exploit-DB GitHub PoC VulnCheck KEV GreyNoise

▸ How to read a CVE - triage first, then detect and patch

This page is every public fact about CVE-2024-38537, cross-linked. Its job is to answer one question fast - does this need my attention now? - and then hand you the two things you do about it. Here is how an analyst reads it.

Triage: should I act now? Four signals, and they are not interchangeable:

CVSSseverity - how bad it is IF exploited, 0-10. A high CVSS alone is not urgency; a flaw can be a perfect 10 and never actually be attacked. EPSSprobability - a model’s estimate of the chance it is exploited in the next 30 days, 0-1. This is the “will it actually happen” signal. CISA KEVconfirmed - it is being exploited in the wild right now. The strongest signal on the page; KEV beats any score. Weaponisedavailability - public exploits / PoCs, and especially Metasploit modules rated Excellent / Great. Reliable, packaged exploit code means low-skill attackers can use it today.

How they combine: KEV, or a dependable Metasploit module, means patch now regardless of CVSS. High CVSS + low EPSS + no exploit is real but not an emergency - schedule it. Low CVSS but KEV-listed still gets patched now. The verdict above already weighed these for you; this is how it got there.

Then what - two workflows:

Detectwhen you cannot patch today, follow this CVE to the ATT&CK techniques it enables, then Build a SIEM detection (the green button) - author a rule, test it in Atomic, deploy it. That buys visibility while the patch waits. PatchAffected products / packages tell you if you are exposed; Fixed versions by distribution and Vendor advisories give the exact version that closes it.

Reading order for the panels below: verdict + badges, then Public exploits / Metasploit (is it weaponised), then ATT&CK techniques + Sigma / IDS rules (can I detect it), then Affected products / packages + Fixed versions (am I exposed, what patches it), then Threat actors / IOCs (who uses it), then Scoring & timeline / references (the evidence).

View attack path from CVE-2024-38537

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ATT&CK techniques

Techniques this CVE enables - linked via CWECAPECATT&CK. High◆ = named directly in ATT&CK or Nuclei templates.

T1055 · Process Injection T1176 · Software Extensions T1195.001 · Compromise Software Dependencies and Development Tools T1505.004 · IIS Components T1505.005 · Terminal Services DLL T1574.006 · Dynamic Linker Hijacking T1574.013 · KernelCallbackTable T1620 · Reflective Code Loading

▤ Build a SIEM detection for these techniques

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CAPEC attack patterns

Attack patterns this CVE enables - the bridge from weakness to ATT&CK technique.

CAPEC-CAPEC-175 · Code Inclusion CAPEC-CAPEC-201 · Serialized Data External Linking CAPEC-CAPEC-228 · DTD Injection CAPEC-CAPEC-251 · Local Code Inclusion CAPEC-CAPEC-252 · PHP Local File Inclusion CAPEC-CAPEC-253 · Remote Code Inclusion CAPEC-CAPEC-263 · Force Use of Corrupted Files CAPEC-CAPEC-538 · Open-Source Library Manipulation CAPEC-CAPEC-549 · Local Execution of Code CAPEC-CAPEC-640 · Inclusion of Code in Existing Process CAPEC-CAPEC-660 · Root/Jailbreak Detection Evasion via Hooking CAPEC-CAPEC-695 · Repo Jacking

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Weakness Classification

CWE-829Inclusion of Functionality from Untrusted Control Sphere

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Affected Products & Versions

ethyca fides< 2.39.1

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Affected Packages

Language-ecosystem packages (from OSV) tied to this CVE, with the version that fixes it - the dependency-level detail NVD doesn’t carry.

PyPI ethyca-fides LOW fixed in 2.39.1

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Public Exploits & PoCs

These PoC and exploit links come from public sources and are not verified to be safe or functional. Review the code before running anything, and treat unverified entries as untrusted.

pocHavoc10-sw/Detect_polyfill_CVE-2024-38537- (nomi-sec)

pocARPSyndicate/cve-scores (trickest)

pocnomi-sec/PoC-in-GitHub (trickest)

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