CVE-2024-6838: MLflow: unconstrained input causes UI denial of service

GHSA-q3gw-8236-5jw4 MEDIUM PoC AVAILABLE CISA: TRACK*
Published March 20, 2025
CISO Take

MLflow v2.13.2 and earlier allow unauthenticated network attackers to crash the UI by submitting experiment names with arbitrarily large integer strings—zero credentials required. If your data science teams run MLflow on accessible networks without an auth proxy, this is exploitable today. Restrict network access immediately, deploy an authentication layer, and plan an upgrade.

Risk Assessment

CVSS 5.3 Medium with EPSS 0.00121—low likelihood of opportunistic exploitation in the wild, but the attack profile (network, no auth, no user interaction, low complexity) makes it trivially executable by any attacker with reachability. The real risk multiplier is organizational: MLflow instances are frequently stood up by data science teams without hardening or network segmentation. Not in CISA KEV. Impact is confined to UI availability; model serving and training jobs are not directly disrupted, but ML operations teams lose experiment visibility and model promotion capability.

Affected Systems

Package Ecosystem Vulnerable Range Patched
mlflow pip No patch
25.7K OpenSSF 4.5 624 dependents Pushed 7d ago 24% patched ~64d to patch Full package profile →
mlflow pip <= 2.13.2 No patch
25.7K OpenSSF 4.5 624 dependents Pushed 7d ago 24% patched ~64d to patch Full package profile →

Severity & Risk

CVSS 3.1
5.3 / 10
EPSS
0.6%
chance of exploitation in 30 days
Higher than 68% 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 Low

Recommended Action

6 steps
  1. Upgrade MLflow past v2.13.2 (monitor upstream GitHub releases for patch).

  2. If immediate upgrade is blocked, firewall MLflow to trusted internal networks only—no public exposure.

  3. Deploy an OAuth2 Proxy or reverse proxy with authentication in front of any MLflow instance; no production tracking server should be unauthenticated.

  4. Add WAF or API gateway rules to reject experiment names exceeding 255 characters.

  5. Audit existing experiments for anomalous artifact_location values (unexpected URIs, relative paths, internal hostnames).

  6. Enable API access logging on MLflow; alert on high-volume experiment creation bursts from single IPs.

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
Article 15 - Accuracy, robustness and cybersecurity
ISO 42001
A.6.2.6 - AI system operational continuity
NIST AI RMF
MANAGE 2.2 - Mechanisms to sustain deployed AI system value
OWASP LLM Top 10
LLM06:2025 - Excessive Agency

Frequently Asked Questions

What is CVE-2024-6838?

MLflow v2.13.2 and earlier allow unauthenticated network attackers to crash the UI by submitting experiment names with arbitrarily large integer strings—zero credentials required. If your data science teams run MLflow on accessible networks without an auth proxy, this is exploitable today. Restrict network access immediately, deploy an authentication layer, and plan an upgrade.

Is CVE-2024-6838 actively exploited?

Proof-of-concept exploit code is publicly available for CVE-2024-6838, increasing the risk of exploitation.

How to fix CVE-2024-6838?

1. Upgrade MLflow past v2.13.2 (monitor upstream GitHub releases for patch). 2. If immediate upgrade is blocked, firewall MLflow to trusted internal networks only—no public exposure. 3. Deploy an OAuth2 Proxy or reverse proxy with authentication in front of any MLflow instance; no production tracking server should be unauthenticated. 4. Add WAF or API gateway rules to reject experiment names exceeding 255 characters. 5. Audit existing experiments for anomalous artifact_location values (unexpected URIs, relative paths, internal hostnames). 6. Enable API access logging on MLflow; alert on high-volume experiment creation bursts from single IPs.

What systems are affected by CVE-2024-6838?

This vulnerability affects the following AI/ML architecture patterns: MLOps platforms, training pipelines, experiment tracking, model registry.

What is the CVSS score for CVE-2024-6838?

CVE-2024-6838 has a CVSS v3.1 base score of 5.3 (MEDIUM). The EPSS exploitation probability is 0.55%.

Technical Details

NVD Description

In mlflow/mlflow version v2.13.2, a vulnerability exists that allows the creation or renaming of an experiment with a large number of integers in its name due to the lack of a limit on the experiment name. This can cause the MLflow UI panel to become unresponsive, leading to a potential denial of service. Additionally, there is no character limit in the `artifact_location` parameter while creating the experiment.

Exploitation Scenario

An attacker discovers an internet-facing MLflow tracking server—common in data science teams that launch `mlflow ui` without authentication. Using curl or a Python script, they POST to /api/2.0/mlflow/experiments/create with an experiment name field containing 500,000 digit integers. The MLflow UI becomes unresponsive for all users within seconds. The SOC sees timeout errors and slow page loads, likely attributing it to a load spike. Meanwhile, ML engineers lose access to experiment comparisons and cannot promote models through the registry—halting a production deployment pipeline. No exploit code required beyond a basic HTTP client.

CVSS Vector

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

Timeline

Published
March 20, 2025
Last Modified
April 1, 2025
First Seen
March 20, 2025

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