Cisco SD-WAN - Peering Activity

Status: production
Group by: dest, new_state, peer_system_ip, peer_type
Author: Nasreddine Bencherchali, Splunk
Source: github.com/splunk/security_content

This analytic detects Cisco SD-WAN control-connection-state-change events where a control connection transitions. It extracts and highlights key triage fields including peer-type, peer-system-ip, public-ip, and public-port. Analysts should manually validate whether the peer-system-ip matches the expected SD-WAN addressing schema and device inventory, whether the event timing aligns with known operational activity (maintenance, failover, or planned changes), and whether the public-ip is an expected source for control peering in the environment. Treat peer-type:vmanage events with higher scrutiny, especially when peer or source IP values are previously unseen.

MITRE ATT&CK coverage

Tactic	Techniques
Initial Access	`T1190` Exploit Public-Facing Application

Rule body splunk

name: Cisco SD-WAN - Peering Activity
id: 1d192a47-4bd3-4c06-902d-5dbe2375ec6d
version: 3
creation_date: '2026-03-03'
modification_date: '2026-05-13'
author: Nasreddine Bencherchali, Splunk
status: production
type: Hunting
description: |
    This analytic detects Cisco SD-WAN `control-connection-state-change` events where a control connection transitions.
    It extracts and highlights key triage fields including `peer-type`, `peer-system-ip`, `public-ip`, and `public-port`.
    Analysts should manually validate whether the `peer-system-ip` matches the expected SD-WAN addressing schema and
    device inventory, whether the event timing aligns with known operational activity (maintenance, failover, or
    planned changes), and whether the `public-ip` is an expected source for control peering in the environment.
    Treat `peer-type:vmanage` events with higher scrutiny, especially when peer or source IP values are previously
    unseen.
data_source:
    - Cisco SD-WAN NTCE 1000001
search: |-
    `cisco_sd_wan_syslog`
    TERM("*control-connection-state-change*")
    TERM("*peer-system-ip:*")
    TERM("*public-ip:*")
    TERM("*new-state:up*")
    | rex field=_raw "^(?<event_timestamp>(?:[A-Z][a-z]{2}\s+\d{1,2}\s+\d{2}:\d{2}:\d{2}(?:\.\d{3})?|[0-9]{4}-[0-9]{2}-[0-9]{2}T[0-9]{2}:[0-9]{2}:[0-9]{2}(?:\.\d{1,6})?(?:Z|[+-][0-9]{2}:[0-9]{2})))\s*:?"
    | rex field=_raw "^(?:[A-Z][a-z]{2}\s+\d{1,2}\s+\d{2}:\d{2}:\d{2}(?:\.\d{3})?\s*:?\s+)(?<prefix_host>[^\s:]+)\s+\S+(?:\[\d+\])?:\s+%"
    | eval dest=coalesce(prefix_host, legacy_host, device_name, host)
    | rex field=_raw "new-state:(?<new_state>\S+)"
    | rex field=_raw "peer-type:(?<peer_type>\S+)"
    | rex field=_raw "peer-system-ip:(?<peer_system_ip>\S+)"
    | rex field=_raw "public-ip:(?<public_ip>\S+)"
    | rex field=_raw "public-port:(?<public_port>\d+)"
    
    | where isnotnull(peer_type) AND isnotnull(peer_system_ip)
    
    | stats count max(event_timestamp) as event_time
                  values(public_ip) as public_ips
                  values(public_port) as public_ports
      by peer_type peer_system_ip dest new_state
    
    | table event_time dest peer_type peer_system_ip
            public_ips public_ports count
    | `cisco_sd_wan___peering_activity_filter`
how_to_implement: |
    This analytic requires Cisco SD-WAN/vSmart logs in Splunk and assumes control peering status
    messages are searchable via the `cisco_sd_wan_syslog` macro. Update that macro with your environment-specific index and sourcetype settings.
    Follow the documentation https://www.cisco.com/c/en/us/td/docs/routers/sdwan/17-x/systems-interfaces/systems-interfaces-guide-17-x/system-logging.html#config-sys-logging to start ingesting these logs.
known_false_positives: |
    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.
references:
    - https://www.cisa.gov/news-events/directives/supplemental-direction-ed-26-03-hunt-and-hardening-guidance-cisco-sd-wan-systems
    - https://blog.talosintelligence.com/uat-8616-sd-wan/
    - https://www.cisco.com/c/en/us/td/docs/routers/sdwan/configuration/Monitor-And-Maintain/monitor-maintain-book/m-alarms-events-logs.html
    - https://www.cisco.com/c/en/us/td/docs/routers/sdwan/17-x/systems-interfaces/systems-interfaces-guide-17-x/system-logging.html#config-sys-logging
    - https://sec.cloudapps.cisco.com/security/center/resources/Cisco-Catalyst-SD-WAN-HardeningGuide
    - https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-sdwan-rpa-EHchtZk
analytic_story:
    - Cisco Catalyst SD-WAN Analytics
asset_type: Network
cve:
    - CVE-2026-20127
mitre_attack_id:
    - T1190
product:
    - Splunk Enterprise
    - Splunk Enterprise Security
    - Splunk Cloud
category: network
security_domain: network
tests:
    - name: True Positive Test
      attack_data:
        - data: https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/cisco_sd_wan/vsyslog/vsyslog.log
          source: /var/log/vsyslog
          sourcetype: cisco:sdwan:syslog
      test_type: unit

Stages and Predicates

Stage 1: `search`

`cisco_sd_wan_syslog`
TERM("*control-connection-state-change*")
TERM("*peer-system-ip:*")
TERM("*public-ip:*")
TERM("*new-state:up*")

Stage 2: `rex`

| rex field=_raw "^(?<event_timestamp>(?:[A-Z][a-z]{2}\s+\d{1,2}\s+\d{2}:\d{2}:\d{2}(?:\.\d{3})?|[0-9]{4}-[0-9]{2}-[0-9]{2}T[0-9]{2}:[0-9]{2}:[0-9]{2}(?:\.\d{1,6})?(?:Z|[+-][0-9]{2}:[0-9]{2})))\s*:?"

Stage 3: `rex`

| rex field=_raw "^(?:[A-Z][a-z]{2}\s+\d{1,2}\s+\d{2}:\d{2}:\d{2}(?:\.\d{3})?\s*:?\s+)(?<prefix_host>[^\s:]+)\s+\S+(?:\[\d+\])?:\s+%"

Stage 4: `eval`

| eval dest=coalesce(prefix_host, legacy_host, device_name, host)

Stage 5: `rex`

| rex field=_raw "new-state:(?<new_state>\S+)"

Stage 6: `rex`

| rex field=_raw "peer-type:(?<peer_type>\S+)"

Stage 7: `rex`

| rex field=_raw "peer-system-ip:(?<peer_system_ip>\S+)"

Stage 8: `rex`

| rex field=_raw "public-ip:(?<public_ip>\S+)"

Stage 9: `rex`

| rex field=_raw "public-port:(?<public_port>\d+)"

Stage 10: `where`

| where isnotnull(peer_type) AND isnotnull(peer_system_ip)

Stage 11: `stats`

| stats count max(event_timestamp) as event_time
              values(public_ip) as public_ips
              values(public_port) as public_ports
  by peer_type peer_system_ip dest new_state

Stage 12: `table`

| table event_time dest peer_type peer_system_ip
        public_ips public_ports count

Stage 13: `search`

| `cisco_sd_wan___peering_activity_filter`

Indicators

Each row is a field, operator, and value that the rule matches. The corpus column counts how many other rules in the catalog look for the same combination: high numbers point to widely-used, community-vetted indicators. Blank or 1 shows that the indicator is specific to this rule.

Field	Kind	Values
`peer_system_ip`	is_not_null	(no value, null check)
`peer_type`	is_not_null	(no value, null check)
`sourcetype`	eq	`cisco:sdwan:syslog`

Search terms

Bare-string tokens in the SPL search body. Splunk matches each token against _raw (the untyped raw event text) anywhere it appears, not against a specific field. These don't surface in the Indicators table because they aren't predicates on a known field.

Stage	Term
1	`"control-connection-state-change"`
1	`"peer-system-ip:"`
1	`"public-ip:"`
1	`"new-state:up"`

Stage	Term
1	`"control-connection-state-change"`
1	`"peer-system-ip:"`
1	`"public-ip:"`
1	`"new-state:up"`

`j` / `k`	Scroll down / up
`d` / `u`	Half-page down / up
`gg` / `G`	Top / bottom
`h` / `l`	History back / forward
`f`	Follow link (`Shift` = new tab)
`/`	Focus search
`?`	Toggle this help
`↑` / `↓`	Navigate search results
`Enter`	Open highlighted result
`Esc`	Close results / dialog

`type:`	`events` / `rules` / `providers`
`vendor:`	`sigma` / `elastic` / `splunk` / `kusto` / `chronicle` (vendor name alone also works: `sigma:`, `kql:`, `secops:`…)
`tactic:`	TA-id, slug, or name: `credential_access`, `TA0006`
`technique:`	technique or sub-technique ID: `T1003`, `T1003.001` (alias `tech:`)
`severity:`	`critical` / `high` / `medium` / `low` / `informational` (alias `sev:`)
`risk_score`	Numeric comparison on the Elastic risk score (0 to 100): `risk_score>50`, `risk_score<=20`, `risk_score=99` (alias `risk`; Elastic rules only)
`stages:`	Rules with exactly N pipeline stages
`correlation:`	`single_event` / `sequence` / `alternatives` / `alternatives_cross_log` / `all_required` / `correlated`
`with:`	Co-occurrence event-id; stacks (`with:4624 with:4769`) to require all, while a comma list in one occurrence (`with:4624,4769`) is an either-or group. Implies multi-event
`like:`	Structural neighbors of a rule slug (equivalents + subsumption stricter / broader): `like:comsvcs_lsass_memory_dump-splunk-sysmon`
`groupby:`	Entity-grouping substring match against `group_by_keys`: `groupby:user`, `groupby:host`
`uses:`	Rules whose predicate tree touches the field (any kind, any value): `uses:CommandLine`
`excludes:`	Rules with top-level `not()` clauses on the field (FP whitelists): `excludes:ParentImage`
`field:` / `value:`	Predicate search; narrows rule cards to those with a matching leaf and drives the indicator tier. Unquoted = substring, wildcards allowed (`value:mimikatz`)
`indicator:`	Shorthand for `field:F value:V`: `indicator:Image=*\powershell.exe`
`kind:`	Filter by predicate kind. Narrows rule cards to those carrying a matching predicate leaf (`vendor:elastic kind:cidr_match`) and drives the indicator tier: `contains` / `starts_with` / `ends_with` / `regex` / `cidr` / `eq` / `in` … (operator aliases `op:`/`match:`)
`has:` / `no:`	`sample`, `field`, `notes`, `refs`, `trace`, `thirdparty`, `rule`, `pattern`, `timewindow`, `threshold`, `newterms`, `sigma`/`elastic`/`splunk`/`kusto`/`chronicle`
`-op:val`	Exclude matches; works on most operators but not `type:`/`like:`/`has:`/`no:` (use `no:<flag>` to exclude a rule flag): `tactic:execution -vendor:splunk`. Standalone `-kind:`/`-field:`/`-value:` drop every rule carrying a matching predicate leaf (`type:rules -kind:is_null`)
`field:"…"` / `value:"…"`	Quoted value = anchored exact match (also allows spaces): `value:"net user"`
`a,b`	Comma = OR inside one operator (`vendor:sigma,elastic`, `severity:high,critical`); repeating a facet merges the same way. `field:`/`value:` never split (literal commas)
`vendors:` / `stage:`	Singular and plural spellings fold to the canonical operator and value: `tactics:` = `tactic:`, `type:event` = `type:events`, `correlation:sequences` = `correlation:sequence`, `has:thresholds` = `has:threshold`
`"quoted phrase"`	Exact-match a multi-word phrase (free text)

Cisco SD-WAN - Peering Activity

MITRE ATT&CK coverage

Rule body splunk

Stages and Predicates

Stage 1: `search`

Stage 2: `rex`

Stage 3: `rex`

Stage 4: `eval`

Stage 5: `rex`

Stage 6: `rex`

Stage 7: `rex`

Stage 8: `rex`

Stage 9: `rex`

Stage 10: `where`

Stage 11: `stats`

Stage 12: `table`

Stage 13: `search`

Indicators

Search terms

Keyboard shortcuts

Search operators

Cisco SD-WAN - Peering Activity

MITRE ATT&CK coverage

Rule body splunk

Stages and Predicates

Stage 1: search

Stage 2: rex

Stage 3: rex

Stage 4: eval

Stage 5: rex

Stage 6: rex

Stage 7: rex

Stage 8: rex

Stage 9: rex

Stage 10: where

Stage 11: stats

Stage 12: table

Stage 13: search

Indicators

Search terms

Stage 1: `search`

Stage 2: `rex`

Stage 3: `rex`

Stage 4: `eval`

Stage 5: `rex`

Stage 6: `rex`

Stage 7: `rex`

Stage 8: `rex`

Stage 9: `rex`

Stage 10: `where`

Stage 11: `stats`

Stage 12: `table`

Stage 13: `search`