Ollama API Accessed from External Network
ELASTIC detection rule by Elastic · Elastic License v2
Detects when the Ollama LLM server accepts connections from external IP addresses. Ollama lacks built-in authentication,
so exposed instances allow unauthenticated model theft, prompt injection, and resource hijacking.
[metadata]
creation_date = "2026/01/09"
integration = ["endpoint"]
maturity = "production"
updated_date = "2026/03/24"
[rule]
author = ["Elastic"]
description = """
Detects when the Ollama LLM server accepts connections from external IP addresses. Ollama lacks built-in authentication,
so exposed instances allow unauthenticated model theft, prompt injection, and resource hijacking.
"""
from = "now-9m"
index = ["logs-endpoint.events.network-*"]
language = "eql"
license = "Elastic License v2"
name = "Ollama API Accessed from External Network"
note = """## Triage and analysis
### Investigating Ollama API Accessed from External Network
This rule detects when Ollama accepts connections from external IP addresses. Ollama binds to localhost:11434 by default but can be exposed via OLLAMA_HOST. Since Ollama lacks authentication, exposed instances allow unauthenticated model theft, prompt injection, and resource hijacking.
### Possible investigation steps
- Check the OLLAMA_HOST environment variable to determine if external exposure was intentional.
- Review the source IP address to identify if it's a known attacker, scanner, or miscategorized internal system.
- Examine Ollama logs for suspicious API calls to /api/pull, /api/push, or /api/generate.
- Check ~/.ollama/models/ for unexpected model downloads that may indicate model poisoning.
- Review network traffic for data exfiltration following the connection.
- Look for child processes spawned by Ollama that may indicate exploitation.
### False positive analysis
- Internal networks not properly classified in CIDR ranges may trigger false positives.
- Load balancers or reverse proxies accessing Ollama from external-facing IPs within trusted infrastructure.
- Legitimate remote access through VPN or authenticated proxy (add proxy IPs to exclusions).
### Response and remediation
- Restrict access immediately by setting OLLAMA_HOST=127.0.0.1:11434 or applying firewall rules.
- If exploitation is suspected, stop Ollama and audit ~/.ollama/models/ for unauthorized models.
- Review Ollama and system logs for signs of compromise.
- Consider running Ollama in a container with network isolation.
"""
references = [
"https://www.greynoise.io/blog/threat-actors-actively-targeting-llms",
"https://atlas.mitre.org/techniques/AML.T0040",
"https://atlas.mitre.org/techniques/AML.T0044",
]
risk_score = 47
rule_id = "d8f2a1b3-c4e5-6789-abcd-ef0123456789"
severity = "medium"
tags = [
"Domain: Endpoint",
"OS: Linux",
"OS: macOS",
"OS: Windows",
"Use Case: Threat Detection",
"Tactic: Initial Access",
"Data Source: Elastic Defend",
"Resources: Investigation Guide",
"Domain: LLM",
"Mitre Atlas: T0040",
"Mitre Atlas: T0044",
]
timestamp_override = "event.ingested"
type = "eql"
query = '''
network where event.action == "connection_accepted" and
process.name in ("ollama", "ollama.exe") and
destination.port == 11434 and
source.ip != null and source.ip != "0.0.0.0" and
not cidrmatch(source.ip,
"10.0.0.0/8",
"127.0.0.0/8",
"169.254.0.0/16",
"172.16.0.0/12",
"192.168.0.0/16",
"100.64.0.0/10",
"::1",
"fe80::/10",
"fc00::/7",
"ff00::/8"
)
'''
[[rule.threat]]
framework = "MITRE ATT&CK"
[[rule.threat.technique]]
id = "T1133"
name = "External Remote Services"
reference = "https://attack.mitre.org/techniques/T1133/"
[[rule.threat.technique]]
id = "T1190"
name = "Exploit Public-Facing Application"
reference = "https://attack.mitre.org/techniques/T1190/"
[rule.threat.tactic]
id = "TA0001"
name = "Initial Access"
reference = "https://attack.mitre.org/tactics/TA0001/"