Abnormally Large DNS Response

Last updated 13 days ago on 2026-04-29

Created 6 years ago on 2020-07-16

About

Specially crafted DNS requests can manipulate a known overflow vulnerability in some Windows DNS servers, resulting in Remote Code Execution (RCE) or a Denial of Service (DoS) from crashing the service.

Tags

Use Case: Threat DetectionTactic: Lateral MovementTactic: ImpactUse Case: VulnerabilityData Source: PAN-OSData Source: Network TrafficLanguage: kuery

Severity

medium

Risk Score

MITRE ATT&CK™

Lateral Movement (TA0008)(external, opens in a new tab or window)

↳ Exploitation of Remote Services (T1210)(external, opens in a new tab or window)

Impact (TA0040)(external, opens in a new tab or window)

↳ Endpoint Denial of Service (T1499)(external, opens in a new tab or window)

False Positive Examples

Environments that leverage DNS responses over 60k bytes will result in false positives - if this traffic is predictable and expected, it should be filtered out. Additionally, this detection rule could be triggered by an authorized vulnerability scan or compromise assessment.

License

Elastic License v2(external, opens in a new tab or window)

Definition

Rule Type

Query (Kibana Query Language)

Integration Pack

Prebuilt Security Detection Rules

Index Patterns

logs-network_traffic.*logs-panw.panos*

Related Integrations

network_traffic(external, opens in a new tab or window)

panw(external, opens in a new tab or window)

Query

✄𐘗text code block:
✄𐘗((event.category:(network or network_traffic) and destination.port:53) 
      or network.protocol:"dns" 
      or data_stream.dataset:(network_traffic.dns or zeek.dns))
    and destination.bytes > 60000
    and event.type:("allowed" or "end" or "protocol" or "start")

Install detection rules in Elastic Security

Detect Abnormally Large DNS Response in the Elastic Security detection engine by installing this rule into your Elastic Stack.

To setup this rule, check out the installation guide for Prebuilt Security Detection Rules(external, opens in a new tab or window).