CVE-2024-22362: Drupal Improper Handling DoS Vulnerability

CVE-2024-22362 Overview

CVE-2024-22362 is a denial-of-service vulnerability in Drupal caused by improper handling of structural elements. Remote attackers can exploit the flaw over the network without authentication or user interaction. Successful exploitation exhausts server resources and renders affected Drupal sites unavailable.

The vulnerability is classified under [CWE-400] (Uncontrolled Resource Consumption). It affects Drupal core versions including 9.3.6. The flaw impacts availability only — confidentiality and integrity are not affected.

Critical Impact
Unauthenticated remote attackers can trigger a denial-of-service condition against Drupal sites by sending crafted requests that abuse improper handling of structural elements.

Affected Products

Drupal core version 9.3.6
Drupal CMS deployments built on affected core releases
Web applications and content sites using vulnerable Drupal versions

Discovery Timeline

2024-01-16 - CVE-2024-22362 published to the National Vulnerability Database
2026-06-17 - Last updated in NVD database

Technical Details for CVE-2024-22362

Vulnerability Analysis

The vulnerability stems from how Drupal processes structural elements during request handling. An attacker can submit crafted input that causes the application to consume excessive server resources. The resulting resource exhaustion produces a denial-of-service condition on the affected web server.

The issue maps to [CWE-400] Uncontrolled Resource Consumption. The Exploit Prediction Scoring System (EPSS) probability is 0.791% at the 51.468 percentile, indicating measurable but not widespread exploitation likelihood. No public proof-of-concept exploit has been published, and the vulnerability is not listed in the CISA Known Exploited Vulnerabilities catalog.

Root Cause

Drupal fails to apply adequate bounds or validation when parsing certain structural elements within incoming requests. Without proper limits, malformed or deeply nested structures force the rendering or parsing pipeline to consume CPU and memory disproportionately. The defect lies in the input handling layer rather than in authentication or output rendering.

Attack Vector

The attack vector is network-based and requires no privileges or user interaction. An attacker sends crafted HTTP requests to a public-facing Drupal endpoint. Repeated requests amplify resource consumption and can degrade or halt service for legitimate users.

No verified public exploit code is available. Refer to the JVN Security Advisory and the Drupal Official Website for additional technical context.

Detection Methods for CVE-2024-22362

Indicators of Compromise

Sudden spikes in CPU or memory utilization on Drupal web nodes correlated with inbound HTTP requests.
Elevated request rates targeting endpoints that process structured form or render data.
PHP-FPM or web worker pool saturation accompanied by increased 5xx responses.
Web server logs showing repeated requests with unusually large or deeply nested payloads.

Detection Strategies

Monitor HTTP request payload sizes and structural depth against established baselines for the application.
Correlate availability alerts with request-pattern anomalies in web access logs.
Apply web application firewall rules that flag oversized or malformed POST bodies sent to Drupal endpoints.

Monitoring Recommendations

Track resource utilization metrics (CPU, memory, worker count) for each Drupal node and alert on sustained saturation.
Aggregate web server, PHP, and reverse-proxy logs into a central analytics platform for cross-source correlation.
Establish alerting thresholds for repeated 5xx errors and timeout responses from /node, form submission, and render endpoints.

How to Mitigate CVE-2024-22362

Immediate Actions Required

Upgrade Drupal core to a fixed release as documented in the official Drupal security advisories.
Inventory all Drupal deployments and identify instances running 9.3.6 or other affected versions.
Place a web application firewall in front of public Drupal sites and enable request-size and rate-limit controls.
Restrict access to administrative and form-processing endpoints where business requirements allow.

Patch Information

Apply the security updates published by the Drupal project. Review the Drupal Core Release Schedule and the GitHub Drupal Repository for current fixed versions and release notes. Validate the patched version in a staging environment before production rollout.

Workarounds

Configure HTTP request size limits and timeouts at the reverse proxy or web server layer.
Rate-limit unauthenticated requests to dynamic Drupal endpoints to reduce amplification potential.
Deploy WAF signatures that block malformed or excessively nested request bodies targeting Drupal.
Scale horizontally and isolate critical sites behind autoscaling load balancers to absorb resource spikes until patching completes.

bash

# Example nginx request-size and rate-limit hardening for a Drupal site
http {
    limit_req_zone $binary_remote_addr zone=drupal_rl:10m rate=10r/s;
    client_max_body_size 8m;
    client_body_timeout 10s;
    client_header_timeout 10s;

    server {
        listen 443 ssl;
        server_name example.com;

        location / {
            limit_req zone=drupal_rl burst=20 nodelay;
            proxy_pass http://drupal_backend;
        }
    }
}