CVE-2024-8063: ollama: divide-by-zero DoS via crafted GGUF model import
HIGH PoC AVAILABLE CISA: TRACK*If your organization runs ollama for local or internal LLM inference, this is a zero-authentication crash vulnerability — any network-reachable ollama instance can be taken down by uploading a crafted GGUF model file. Update to a patched version immediately and restrict the ollama API (port 11434) to trusted internal users only. This is especially urgent for teams where ollama backs production AI agents or internal tooling with uptime requirements.
Risk Assessment
High exploitability: CVSS 7.5, network-accessible, no authentication required, no user interaction needed. Impact is limited to availability (no confidentiality or integrity loss), but ollama is widely deployed in enterprise AI stacks as a local inference backend. Default ollama installations expose the API on all interfaces without authentication, making internet-exposed or broadly accessible internal instances immediately vulnerable. Blast radius scales with how many AI-dependent workflows depend on the crashed instance.
Affected Systems
| Package | Ecosystem | Vulnerable Range | Patched |
|---|---|---|---|
| ollama | pip | — | No patch |
Do you use ollama? You're affected.
Severity & Risk
Attack Surface
Recommended Action
6 steps-
PATCH
Upgrade ollama to the latest version (>v0.3.3) immediately.
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NETWORK
Firewall port 11434 — bind ollama to 127.0.0.1 only unless remote access is required (
OLLAMA_HOST=127.0.0.1). -
AUTH
Place a reverse proxy with authentication (nginx + basic auth or mTLS) in front of any network-exposed ollama instance.
-
INPUT VALIDATION
Only allow model imports from trusted, verified sources — enforce an internal model registry.
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MONITORING
Alert on unexpected ollama process restarts or crash loops, which may indicate exploitation attempts.
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DETECTION
Log all
/api/pulland model import requests; anomalousblock_countvalues in GGUF metadata should trigger investigation.
CISA SSVC Assessment
Source: CISA Vulnrichment (SSVC v2.0). Decision based on the CISA Coordinator decision tree.
Classification
Compliance Impact
This CVE is relevant to:
Frequently Asked Questions
What is CVE-2024-8063?
If your organization runs ollama for local or internal LLM inference, this is a zero-authentication crash vulnerability — any network-reachable ollama instance can be taken down by uploading a crafted GGUF model file. Update to a patched version immediately and restrict the ollama API (port 11434) to trusted internal users only. This is especially urgent for teams where ollama backs production AI agents or internal tooling with uptime requirements.
Is CVE-2024-8063 actively exploited?
Proof-of-concept exploit code is publicly available for CVE-2024-8063, increasing the risk of exploitation.
How to fix CVE-2024-8063?
1. PATCH: Upgrade ollama to the latest version (>v0.3.3) immediately. 2. NETWORK: Firewall port 11434 — bind ollama to 127.0.0.1 only unless remote access is required (`OLLAMA_HOST=127.0.0.1`). 3. AUTH: Place a reverse proxy with authentication (nginx + basic auth or mTLS) in front of any network-exposed ollama instance. 4. INPUT VALIDATION: Only allow model imports from trusted, verified sources — enforce an internal model registry. 5. MONITORING: Alert on unexpected ollama process restarts or crash loops, which may indicate exploitation attempts. 6. DETECTION: Log all `/api/pull` and model import requests; anomalous `block_count` values in GGUF metadata should trigger investigation.
What systems are affected by CVE-2024-8063?
This vulnerability affects the following AI/ML architecture patterns: LLM inference servers, RAG pipelines, agent frameworks, local AI deployment, model serving.
What is the CVSS score for CVE-2024-8063?
CVE-2024-8063 has a CVSS v3.1 base score of 7.5 (HIGH). The EPSS exploitation probability is 0.07%.
Technical Details
NVD Description
A divide by zero vulnerability exists in ollama/ollama version v0.3.3. The vulnerability occurs when importing GGUF models with a crafted type for `block_count` in the Modelfile. This can lead to a denial of service (DoS) condition when the server processes the model, causing it to crash.
Exploitation Scenario
An adversary identifies an internal ollama deployment (e.g., via port scan on 11434 or via supply-chain access to a developer machine). They craft a GGUF model file with an invalid or unexpected data type for the `block_count` field in the model metadata. Without authentication, they POST the malicious model to the ollama `/api/pull` or model import endpoint. The server attempts to parse the GGUF metadata, performs an arithmetic operation using the malformed `block_count` value, hits a divide-by-zero, and crashes. All AI services dependent on that ollama instance go offline. The attacker can repeat this to maintain a persistent DoS if the endpoint remains open and unpatched.
Weaknesses (CWE)
CVSS Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H References
- huntr.com/bounties/fd8e1ed6-21d2-4c9e-8395-2098f11b7db9 Exploit 3rd Party
- github.com/ARPSyndicate/cve-scores Exploit
- github.com/fkie-cad/nvd-json-data-feeds Exploit
Timeline
Related Vulnerabilities
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Same package: ollama CVE-2024-37032 8.8 Ollama: path traversal enables RCE via model blob API
Same package: ollama CVE-2024-39720 8.2 Ollama: OOB read in GGUF parser enables remote DoS
Same package: ollama
AI Threat Alert