External risk intelligence

Clerk WordPress Plugin Time-Based API Key Validation Vulnerability

CVE advisorySeverity: HIGH (CVSS 7.5)

CVE-2022-3907

The Clerk WordPress plugin is vulnerable to time-based attacks in its API request validation function. Attackers can exploit this by sending crafted requests to infer sensitive API key information, potentially leading to unauthorized access. This is a concern for any WordPress site using the Clerk plugin for API calls.

4Halo Surface Signal

Clerk Io

before 4.0.0

External exposure likelihood

Halo Surface Signal score for CVE-2022-3907

The vulnerability affects a WordPress plugin that handles API requests. WordPress sites and their associated API endpoints are commonly deployed as public-facing web services, making this component reachable from the internet in typical deployments.

PCI scan relevance

PCI Relevance for CVE-2022-3907

Yes

CVE-2022-3907 — Halo PCI Relevance: Yes. Under typical PCI ASV external scan criteria, this issue may be flagged for scan prioritization.

This CVE is PCI relevant as it enables unauthenticated attackers to steal sensitive data due to sensitive data exposure, a class of vulnerability that would cause an ASV scan to fail.

Scan-prioritization guidance only—not a PCI DSS certification or ASV attestation.

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

Horizon Alert

Summary of the vulnerability and why it matters

The Clerk WordPress plugin has a vulnerability that could allow attackers to infer sensitive information by observing response times to specially crafted requests. This could potentially lead to unauthorized access or data exposure. The main concern is confirming relevance and exposure to specific business data.

  • Plugin allows guessing sensitive data.
  • Matters if your site uses Clerk for API calls.
  • Verify if your WordPress site is impacted.

Attack Path

How an attacker could exploit the issue

An attacker could target any WordPress site using the Clerk plugin by sending specially crafted API requests. The plugin's validation function for these requests, which checks API keys against stored values, is susceptible to time-based attacks. This occurs because the comparison operators used don't immediately reject invalid keys, allowing an attacker to infer correct key details over time, potentially leading to unauthorized access or information disclosure.

  • No special access needed.
  • API request validation.
  • Risk of information disclosure.

Live Threat

Current exploitation, exposure, and threat context

This vulnerability could expose sensitive API keys used by the Clerk WordPress plugin. When the plugin's validation function improperly compares API keys through time-based attacks, an attacker could potentially determine the correct API key. This could lead to unauthorized access to plugin functionalities.

  • Plugin API keys could be exposed.
  • Time-based comparison may reveal keys.
  • Unauthorized access to plugin functions.

Priority actions

Operational Fix

Recommended remediation, mitigation, and detection steps

Application owners and infrastructure teams responsible for WordPress sites should prioritize understanding this vulnerability's impact. The first practical step is to identify all instances of the Clerk WordPress plugin, confirm its reachability and business criticality, and then coordinate with the relevant team to plan remediation.

  • WordPress site owners should lead remediation efforts.
  • Verify plugin presence and public accessibility.
  • Plan updates or vendor engagement.

Frequently asked questions

What is the Clerk WordPress plugin?

The Clerk plugin is an add-on for WordPress websites that integrates tools from Clerk.io. It is primarily used to manage e-commerce features like personalized search, product recommendations, and automated marketing communications. By connecting a WordPress site to the Clerk.io platform, it handles various API requests to synchronize data and maintain these user-facing services.

How does CVE-2022-3907 function?

This vulnerability is classified as a CWE-203 weakness, which relates to discrepancies in how software handles inputs. Because the plugin uses standard comparison operators to check API keys, it takes slightly different amounts of time to process a correct character versus an incorrect one. An attacker can measure these microscopic timing differences to systematically guess a valid API key, character by character, without needing prior access or credentials.

Do I need to be authenticated to trigger this flaw?

No, you do not need to be an authenticated user or have any special privileges to trigger this vulnerability. The issue exists within the validation logic for incoming API requests. It is important to note that this is not triggered by standard browsing or regular site navigation, but specifically through crafted API requests designed to measure the plugin's response time during key verification.

Is my site at risk if I use this plugin?

Halo Surface Signal indicates that because this plugin handles API requests on WordPress sites, it is typically reachable from the internet. This makes it a potential target for external actors. You should consider your site at risk if you are running a version of the Clerk plugin earlier than 4.0.0, as the API validation mechanism remains exposed to time-based inference in those older versions.

What is the first step to address CVE-2022-3907?

Start by auditing your WordPress environment to identify if the Clerk plugin is installed and which version is active. If you find a version prior to 4.0.0, prioritize updating the plugin immediately to reach a secure baseline. If an update cannot be performed right away, evaluate the business necessity of the plugin and consider temporarily disabling it to eliminate the external attack surface until a patch is applied.

References

Sources and related resources

Primary sources: NVD, CVE.org.

NVDPublished Modified