Cisco SD-WAN - Low Frequency Rogue Peer
This analytic identifies low-frequency Cisco SD-WAN control peering activity from control-connection-state-change events where "new-state:up". It extracts "peer-type" and "peer-system-ip", groups events by these two…
Description
This analytic identifies low-frequency Cisco SD-WAN control peering activity from control-connection-state-change events where "new-state:up". It extracts "peer-type" and "peer-system-ip", groups events by these two fields, and counts how often each combination appears within the selected time window. Combinations whose count is less than or equal to the defined threshold (currently <=3 occurrences in the search window) are flagged as rare. Analysts should prioritize peer identities that are rarely observed in the environment, particularly those involving unexpected peer-type roles or unfamiliar peer-system-ip values. Rare control-plane peers may indicate misconfiguration, unauthorized SD-WAN components, infrastructure drift, or potentially malicious control-plane connection attempts. Findings might indicate the potential exploitation of CVE-2026-20127. Note that the threshold setting is set to "3", but its highly recommended that this should be adapted to the environment before deploying this search.
Detection logic
Detection requirements
- Platform
- ContainersESXiIaaSLinuxmacOSNetwork DevicesWindows
The rule states no platform. This is derived from the ATT&CK technique it maps to.
- Log source category
- cisco_sd_wan_ntce_1000001
Known benign triggers
- New controller onboarding, topology expansion, controller failover, maintenance windows, and temporary transport. Path changes can create rare peer/public-IP combinations. Validate outliers against change records and known SD-WAN inventory before escalating.
MITRE ATT&CK mappings
0 exclusive techniques.This is coverage no other published rule has; it is not this rule's total technique count.
References
From the source
- At source
- Open at source
- Upstream identifier
- 0fe052a5-07b8-48e7-9fc8-d6a3957eb914
- Tagged by the source as
- Cisco Catalyst SD-WAN AnalyticsNetworknetworkSplunk CloudSplunk EnterpriseSplunk Enterprise Securitynetwork
Licence
- Published under
- Apache License 2.0Read the licence
- Attribution
- Required
- Obtained under
- Apache-2.0Read the origin licence
Authorship
- Written by
- Published
- Aug 26, 2026
- Version
- 1