Cisco Duo Policy Deny Access
The following analytic identifies instances where a Duo administrator creates or updates a policy to explicitly deny user access within the Duo environment. It detects this behavior by searching Duo administrator…
Description
The following analytic identifies instances where a Duo administrator creates or updates a policy to explicitly deny user access within the Duo environment. It detects this behavior by searching Duo administrator activity logs for policy creation or update actions where the authentication status is set to "Deny access." By correlating these events with user and admin details, the analytic highlights potential misuse or malicious changes to access policies. This behavior is critical for a SOC to monitor, as unauthorized or suspicious denial of access policies can indicate insider threats, account compromise, or attempts to disrupt legitimate user access. The impact of such an attack may include denial of service to critical accounts, disruption of business operations, or the masking of further malicious activity by preventing targeted users from accessing resources. Early detection enables rapid investigation and remediation to maintain organizational security and availability.
Detection logic
Detection requirements
- Platform
- IaaSIdentity ProviderLinuxmacOSNetwork DevicesOffice SuiteSaaSWindows
The rule states no platform. This is derived from the ATT&CK technique it maps to.
- Log source category
- cisco_duo_administrator
Known benign triggers
- No false positives have been identified at this time.
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
| Reference | Cited by |
|---|---|
| splunkbase.splunk.com/app/7404 | 14 |
From the source
- At source
- Open at source
- Upstream identifier
- abf39464-ed43-4d69-a56c-02750032a3fb
- Tagged by the source as
- Cisco Duo Suspicious ActivityIdentityapplicationSplunk CloudSplunk EnterpriseSplunk Enterprise Securityidentity
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