Detection rules › Splunk

Cisco Duo Policy Allow Old Flash

Status
production
Severity
medium
Group by
action, actionlabel, admin_email, description, user
Author
Patrick Bareiss, Splunk
Source
github.com/splunk/security_content

The following analytic identifies instances where a Duo administrator creates or updates a policy to allow the use of outdated Flash components, specifically by detecting policy changes with the flash_remediation=no remediation attribute. It leverages Duo activity logs ingested via the Cisco Security Cloud App, searching for policy_update or policy_create actions and parsing the policy description for indicators of weakened security controls. This behavior is significant for a SOC because permitting old Flash increases the attack surface, as Flash is widely known for its security vulnerabilities and is no longer supported. Attackers may exploit such policy changes to bypass security controls, introduce malware, or escalate privileges within the environment. Detecting and responding to these policy modifications helps prevent potential exploitation, reduces organizational risk, and ensures adherence to security best practices. Immediate investigation is recommended to determine if the change was authorized or indicative of malicious activity.

MITRE ATT&CK coverage

Rule body splunk

name: Cisco Duo Policy Allow Old Flash
id: f36c0d3f-d57f-4b88-a5d4-0a4c9a0752f6
version: 6
creation_date: '2025-07-10'
modification_date: '2026-05-13'
author: Patrick Bareiss, Splunk
status: production
type: TTP
description: The following analytic identifies instances where a Duo administrator creates or updates a policy to allow the use of outdated Flash components, specifically by detecting policy changes with the flash_remediation=no remediation attribute. It leverages Duo activity logs ingested via the Cisco Security Cloud App, searching for policy_update or policy_create actions and parsing the policy description for indicators of weakened security controls. This behavior is significant for a SOC because permitting old Flash increases the attack surface, as Flash is widely known for its security vulnerabilities and is no longer supported. Attackers may exploit such policy changes to bypass security controls, introduce malware, or escalate privileges within the environment. Detecting and responding to these policy modifications helps prevent potential exploitation, reduces organizational risk, and ensures adherence to security best practices. Immediate investigation is recommended to determine if the change was authorized or indicative of malicious activity.
data_source:
    - Cisco Duo Administrator
search: |-
    `cisco_duo_administrator` action=policy_update OR action=policy_create
    | spath input=description
    | search flash_remediation="no remediation"
    | rename object as user
    | stats count min(_time) as firstTime max(_time) as lastTime
      BY action actionlabel description
         user admin_email
    | `security_content_ctime(firstTime)`
    | `security_content_ctime(lastTime)`
    | `cisco_duo_policy_allow_old_flash_filter`
how_to_implement: The analytic leverages Duo activity logs to be ingested using the Cisco Security Cloud App (https://splunkbase.splunk.com/app/7404).
known_false_positives: No false positives have been identified at this time.
references:
    - https://splunkbase.splunk.com/app/7404
drilldown_searches:
    - name: View the detection results for - "$user$"
      search: '%original_detection_search% | search  user = "$user$"'
      earliest_offset: $info_min_time$
      latest_offset: $info_max_time$
    - name: View risk events for the last 7 days for - "$user$"
      search: '| from datamodel Risk.All_Risk | search normalized_risk_object IN ("$user$") | stats count min(_time) as firstTime max(_time) as lastTime values(search_name) as "Search Name" values(risk_message) as "Risk Message" values(analyticstories) as "Analytic Stories" values(annotations._all) as "Annotations" values(annotations.mitre_attack.mitre_tactic) as "ATT&CK Tactics" by normalized_risk_object | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)`'
      earliest_offset: 7d
      latest_offset: "0"
finding:
    title: A policy has been created or updated to allow old flash by user $user$ with email $admin_email$
    entity:
        field: user
        type: user
        score: 50
analytic_story:
    - Cisco Duo Suspicious Activity
asset_type: Identity
mitre_attack_id:
    - T1556
product:
    - Splunk Enterprise
    - Splunk Enterprise Security
    - Splunk Cloud
category: application
security_domain: identity
tests:
    - name: True Positive Test
      attack_data:
        - data: https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1556/cisco_duo_policy_allow_old_flash_and_java/cisco_duo_administrator.json
          source: duo
          sourcetype: cisco:duo:administrator
      test_type: unit

Stages and Predicates

Stage 1: search

`cisco_duo_administrator` action=policy_update OR action=policy_create

Stage 2: spath

| spath input=description

Stage 3: search

| search flash_remediation="no remediation"

Stage 4: rename

| rename object as user

Stage 5: stats

| stats count min(_time) as firstTime max(_time) as lastTime
  BY action actionlabel description
     user admin_email

Stage 6: search

| `security_content_ctime(firstTime)`

Stage 7: search

| `security_content_ctime(lastTime)`

Stage 8: search

| `cisco_duo_policy_allow_old_flash_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.

FieldKindValues
actioneq
  • policy_create
  • policy_update
flash_remediationeq
  • "no remediation"
sourcetypeeq
  • cisco:duo:administrator