CVE-2024-8053: Open WebUI unauthenticated PDF

Q: Is CVE-2024-8053 actively exploited?

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

Q: 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.

Q: 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.

Q: 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 0.60%.

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.

What is the risk?

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.

What systems are affected?

Package	Ecosystem	Vulnerable Range	Patched
Open WebUI	pip	<= 0.3.10	No patch
142.4K Pushed 4d ago 77% patched ~5d to patch Full package profile →

Do you use Open WebUI? You're affected.

How severe is it?

CVSS 3.1

7.5 / 10

EPSS

0.6%

chance of exploitation in 30 days

Higher than 44% of all CVEs

Source: EPSS v3 — FIRST.org

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, VulnCheck KEV, CISA SSVC, EPSS, Metasploit, Exploit-DB, trickest/cve, Nuclei templates, and inthewild.io exploitation reports.

What is the attack surface?

AV Network

AC Low

PR None

UI None

S Unchanged

C None

I None

A High

What should I do?

6 steps

IMMEDIATE

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

What does CISA's SSVC say?

Decision Track*

Exploitation poc

Automatable Yes

Technical Impact partial

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

How is it classified?

Auth Bypass DoS API Inference AML.T0029 - Denial of AI Service AML.T0034 - Cost Harvesting AML.T0049 - Exploit Public-Facing Application

Which compliance frameworks are affected?

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 0.60%.

What is the AI security impact?

Affected AI Architectures

LLM web interfacesself-hosted AI deploymentsmodel serving

MITRE ATLAS Techniques

AML.T0029 Denial of AI Service

AML.T0034 Cost Harvesting

AML.T0049 Exploit Public-Facing Application

Compliance Controls Affected

EU AI Act: Art. 15

ISO 42001: A.6.2

NIST AI RMF: GOVERN 1.2

OWASP LLM Top 10: LLM04

What are the technical details?

Original Advisory

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.

Weaknesses (CWE)

CWE-287 Improper Authentication Primary CWE-306 Missing Authentication for Critical Function Primary

CWE-287 — Improper Authentication: When an actor claims to have a given identity, the product does not prove or insufficiently proves that the claim is correct.