CVE-2024-8053: Open-WebUI: unauthenticated PDF endpoint enables DoS

GHSA-9vf8-xgwm-97r8 HIGH PoC AVAILABLE CISA: TRACK*
Published March 20, 2025
CISO Take

Open-WebUI's PDF generation endpoint is fully exposed without authentication in v0.3.10 and earlier, allowing any unauthenticated attacker to exhaust server resources or abuse the service at zero cost. If your team runs self-hosted LLM interfaces via Open-WebUI, treat this instance as internet-exposed until patched and firewall-restricted. Restrict network access at the reverse proxy layer immediately and upgrade as soon as a patched release is available.

Risk Assessment

CVSS 7.5 HIGH with network-accessible, zero-privilege attack path. EPSS 0.78% suggests limited active exploitation at time of publication, but the trivial exploitation path (single unauthenticated POST request) and the rapid adoption of Open-WebUI in enterprise AI sandbox environments elevates the practical risk. Not in CISA KEV. Primary risk is availability of AI assistant infrastructure; secondary risk is financial/operational from compute abuse. Organizations exposing Open-WebUI directly to the internet are at immediate risk.

Affected Systems

Package Ecosystem Vulnerable Range Patched
open-webui pip <= 0.3.10 No patch
135.3K Pushed 8d ago 58% patched ~9d to patch Full package profile →

Do you use open-webui? You're affected.

Severity & Risk

CVSS 3.1
7.5 / 10
EPSS
0.7%
chance of exploitation in 30 days
Higher than 73% of all CVEs
Exploitation Status
Exploit Available
Exploitation: MEDIUM
Sophistication
Trivial
Exploitation Confidence
medium
CISA SSVC: Public PoC
Public PoC indexed (trickest/cve)
Composite signal derived from CISA KEV, CISA SSVC, EPSS, trickest/cve, and Nuclei templates.

Attack Surface

AV AC PR UI S C I A
AV Network
AC Low
PR None
UI None
S Unchanged
C None
I None
A High

Recommended Action

6 steps
  1. IMMEDIATE

    Restrict network access to Open-WebUI via firewall or reverse proxy — it should never be internet-exposed without authentication.

  2. Block or rate-limit the /api/v1/utils/pdf endpoint at the reverse proxy layer (nginx/Traefik) until an official patch is available.

  3. Upgrade Open-WebUI to the latest available release beyond v0.3.10 and verify the patch addresses endpoint authentication.

  4. Audit all Open-WebUI endpoints for similar missing authentication patterns using the Huntr advisory as a baseline.

  5. Add payload size limits at the reverse proxy layer (e.g., client_max_body_size in nginx).

  6. Monitor logs for anomalous POST activity to /api/v1/utils/ paths as a detection signal.

CISA SSVC Assessment

Decision Track*
Exploitation poc
Automatable Yes
Technical Impact partial

Source: CISA Vulnrichment (SSVC v2.0). Decision based on the CISA Coordinator decision tree.

Classification

Compliance Impact

This CVE is relevant to:

EU AI Act
Art. 15 - Accuracy, Robustness and Cybersecurity
ISO 42001
A.6.2 - AI System Access Control
NIST AI RMF
GOVERN 1.2 - Accountability and Risk Ownership
OWASP LLM Top 10
LLM04 - Model Denial of Service

Frequently Asked Questions

What is CVE-2024-8053?

Open-WebUI's PDF generation endpoint is fully exposed without authentication in v0.3.10 and earlier, allowing any unauthenticated attacker to exhaust server resources or abuse the service at zero cost. If your team runs self-hosted LLM interfaces via Open-WebUI, treat this instance as internet-exposed until patched and firewall-restricted. Restrict network access at the reverse proxy layer immediately and upgrade as soon as a patched release is available.

Is CVE-2024-8053 actively exploited?

Proof-of-concept exploit code is publicly available for CVE-2024-8053, increasing the risk of exploitation.

How to fix CVE-2024-8053?

1. IMMEDIATE: Restrict network access to Open-WebUI via firewall or reverse proxy — it should never be internet-exposed without authentication. 2. Block or rate-limit the /api/v1/utils/pdf endpoint at the reverse proxy layer (nginx/Traefik) until an official patch is available. 3. Upgrade Open-WebUI to the latest available release beyond v0.3.10 and verify the patch addresses endpoint authentication. 4. Audit all Open-WebUI endpoints for similar missing authentication patterns using the Huntr advisory as a baseline. 5. Add payload size limits at the reverse proxy layer (e.g., client_max_body_size in nginx). 6. Monitor logs for anomalous POST activity to /api/v1/utils/ paths as a detection signal.

What systems are affected by CVE-2024-8053?

This vulnerability affects the following AI/ML architecture patterns: LLM web interfaces, self-hosted AI deployments, model serving.

What is the CVSS score for CVE-2024-8053?

CVE-2024-8053 has a CVSS v3.1 base score of 7.5 (HIGH). The EPSS exploitation probability is 0.73%.

Technical Details

NVD Description

In version v0.3.10 of open-webui/open-webui, the `api/v1/utils/pdf` endpoint lacks authentication mechanisms, allowing unauthenticated attackers to access the PDF generation service. This vulnerability can be exploited by sending a POST request with an excessively large payload, potentially leading to server resource exhaustion and denial of service (DoS). Additionally, unauthorized users can misuse the endpoint to generate PDFs without verification, resulting in service misuse and potential operational and financial impacts.

Exploitation Scenario

An attacker discovers an internet-exposed Open-WebUI instance via Shodan or Censys (easily fingerprinted by UI assets). Without credentials, they send a loop of POST requests to /api/v1/utils/pdf with multi-megabyte HTML payloads. The server's PDF rendering process (headless browser or wkhtmltopdf) spawns repeatedly, consuming CPU and memory until the host becomes unresponsive. Legitimate users lose access to the LLM interface entirely. In a parallel scenario, a cost-conscious adversary uses the unauthenticated endpoint to generate thousands of PDFs — effectively using victim infrastructure as a free document rendering service — without triggering any authentication or billing controls.

CVSS Vector

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

Timeline

Published
March 20, 2025
Last Modified
March 27, 2025
First Seen
March 24, 2026

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