CVE-2024-12537 Open WebUI Code Format DoS Lab

This repository contains a local, isolated reproduction lab and nuclei template candidate for CVE-2024-12537, an unauthenticated denial-of-service vulnerability in Open WebUI's code formatting endpoint.

The lab does not send large denial-of-service payloads. It validates the nuclei detection logic through Open WebUI's unauthenticated /api/version fingerprint endpoint and a minimal {"code":"x"} request to /api/v1/utils/code/format, then compares a vulnerable version with a patched/newer version.

Summary

• Product: open-webui/open-webui
• Vulnerability: Unauthenticated uncontrolled resource consumption / denial of service
• CVE: CVE-2024-12537
• GHSA: GHSA-chf7-q7m5-fq92
• Affected endpoint: POST /api/v1/utils/code/format
• Fingerprint endpoint used by this lab: GET /api/version
• Vulnerable version validated: v0.5.10
• Patched/newer version validated: v0.6.14
• Nuclei cutoff used here: < 0.5.14 for the unauthenticated threat model

References:

• https://nvd.nist.gov/vuln/detail/CVE-2024-12537
• https://github.com/advisories/GHSA-chf7-q7m5-fq92
• https://huntr.com/bounties/edabd06c-acc0-428c-a481-271f333755bc

Files

• docker-compose.yml: starts Open WebUI with a selectable Docker tag
• verify-cve-2024-12537.sh: waits for readiness, prints /api/version, and runs nuclei when available
• nuclei/CVE-2024-12537.yaml: nuclei template candidate

Requirements

• Docker Engine or Docker Desktop
• curl
• Optional: nuclei

Run this only in a local isolated lab. Do not use these commands against third-party systems. Use only against systems you own or have explicit written authorization to test.

Reproduce Vulnerable-Version Detection

Start Open WebUI v0.5.10:

WEBUI_TAG=v0.5.10 docker compose up -d

Run the verification script:

sh verify-cve-2024-12537.sh

Observed vulnerable-version response:

HTTP/1.1 200 OK
content-type: application/json

{"version":"0.5.10"}

Observed vulnerable-version nuclei output:

[CVE-2024-12537:dsl-1] [http] [high] http://127.0.0.1:3010/api/v1/utils/code/format ["0.5.10"]

Clean up:

docker compose down -v

Reproduce Patched/Newer-Version Control

Start Open WebUI v0.6.14:

WEBUI_TAG=v0.6.14 docker compose up -d

Run the verification script:

sh verify-cve-2024-12537.sh

Observed patched/newer-version response:

HTTP/1.1 200 OK
content-type: application/json

{"version":"0.6.14"}

Observed patched/newer-version nuclei output:

No results found

Clean up:

docker compose down -v

Nuclei

Validate the template:

nuclei -validate -t nuclei/CVE-2024-12537.yaml

Run against the local lab:

nuclei -silent \
  -t nuclei/CVE-2024-12537.yaml \
  -include-templates nuclei/CVE-2024-12537.yaml \
  -u http://127.0.0.1:3010

Expected behavior:

• v0.5.10: match
• v0.6.14: no match

Notes

• The template intentionally avoids sending a large request body to /api/v1/utils/code/format.
• The endpoint proof uses only {"code":"x"}, which returned {"code":"x\n"} on Docker v0.5.10 and {"detail":"Not authenticated"} on Docker v0.6.14.
• The example nuclei command includes -include-templates because templates tagged dos may be excluded by default.
• Some Open WebUI versions briefly return curl: (52) Empty reply from server while the application is still starting. The verification script waits until /api/version responds.
• docker-compose.yml sets RAG_EMBEDDING_MODEL="" and RAG_EMBEDDING_MODEL_AUTO_UPDATE=False so the lab does not block on embedding model initialization.
• GitHub Advisory currently lists package affected versions as <= 0.3.32; this lab uses the unauthenticated code-path cutoff < 0.5.14 based on commit tracing. The relevant sequence is d3d161f72 (no authentication, v0.5.0-v0.5.13), 2f75eef49 (adds get_verified_user, v0.5.14+), and 4fe45d443 (hardens to get_admin_user, v0.6.14+).
• No real-world targets were used.