Nuxt OG Image is vulnerable to Denial of Service via unbounded image dimensions

Product: Nuxt OG Image
Version: 6.1.2
CWE-ID: CWE-404: Improper Resource Shutdown or Release
Description: Failure to limit the length and width of the generated image results in a denial of service.
Impact: Denial of service
Exploitation condition: An external user
Mitigation: Implement a limitation on the width and length of the generated image.
Researcher: Dmitry Prokhorov (Positive Technologies)

Research

During the analysis of the nuxt-og-image package, which is shipped with the nuxt-seo package, a zero‑day vulnerability was discovered.
This research revealed that the image‑generation component by the URI: /_og/d/ (and, in older versions, /og-image/) contains a Denial of Service (DoS) vulnerability. The issue arises because there is no restriction on the width and height parameters of the generated image. The vulnerability was reproduced using the standard configuration and the default templates.

Listing 1. The content of the configuration file nuxt.config.ts

export default defineNuxtConfig({
  modules: ['nuxt-og-image'],
  devServer: {
    host: 'web-test.local',
    port: 3000
  },
  site: {
    url: 'http://web-test.local:3000',
  },
  ogImage: {
    fonts: [
      'Inter:400', 
      'Inter:700'
    ],
  }
})

Vulnerability reproduction

To demonstrate the proof‑of‑concept, a request should be sent with the increased width and height parameters. This will cause a delay and exhaust the server’s resources during image generation.

Listing 2. HTTP-request example

GET /_og/d/og.png?width=20000&height=20000 HTTP/1.1
Host: web-test.local:3000

Figure 1. HTTP-response: denial-of-service error
<img width="974" height="663" alt="image" src="https://github.com/user-attachments/assets/ff625249-2e0d-4a03-a734-3a77fd0cbb81" />

After sending a HTTP-request, the test server's memory was exhausted.

Figure 2. Video memory exhausted error
<img width="863" height="1033" alt="image" src="https://github.com/user-attachments/assets/66b5919a-f039-468e-812e-1f709c468287" />

Credits

Researcher: Dmitry Prokhorov (Positive Technologies)