Detection rules › Splunk
Cisco Duo Policy Allow Old Flash
The following analytic identifies instances where a Duo administrator creates or updates a policy to allow the use of outdated Flash components, specifically by detecting policy changes with the flash_remediation=no remediation attribute.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.
Known false positives
- No false positives have been identified at this time.
MITRE ATT&CK coverage
| Tactic | Techniques |
|---|---|
| Persistence | |
| Defense Impairment | |
| Credential Access |
Rule body
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The following analytic identifies instances where a Duo administrator creates or updates a policy to allow the use of outdated Flash components, specifically by detecting policy changes with the flash_remediation=no remediation attribute.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
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
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
These rows show field, operator, and value matches.
| Field | Kind | Values | Search |
|---|---|---|---|
action | eq |
| field:"action" kind:eq |
flash_remediation | eq |
| field:"flash_remediation" kind:eq |
sourcetype | eq |
| field:"sourcetype" kind:eq value:"cisco:duo:administrator" |