CVE-2025-20267 Overview
CVE-2025-20267 is a stored cross-site scripting (XSS) vulnerability in the web-based management interface of Cisco Identity Services Engine (ISE). The flaw stems from insufficient validation of user-supplied input, allowing an authenticated administrator to inject malicious script into specific interface pages. When another user loads the affected page, the browser executes the attacker-controlled script in the context of the ISE interface. Successful exploitation can expose sensitive browser-based information or hijack administrative sessions. The weakness is tracked as [CWE-80] (Improper Neutralization of Script-Related HTML Tags in a Web Page).
Critical Impact
Authenticated attackers with administrative credentials can execute arbitrary script in the browser session of ISE interface users, enabling session token theft and follow-on privilege abuse across the identity infrastructure.
Affected Products
- Cisco Identity Services Engine 3.2.0 and patches 1 through 7
- Cisco Identity Services Engine 3.3.0 and patches 1 through 4
- Cisco Identity Services Engine 3.4.0
Discovery Timeline
- 2025-05-21 - CVE-2025-20267 published to NVD
- 2026-06-17 - Last updated in NVD database
Technical Details for CVE-2025-20267
Vulnerability Analysis
Cisco ISE is a network access control and identity policy platform used to authenticate and authorize endpoints connecting to enterprise networks. Its administrative web interface exposes forms and configuration objects that accept operator-supplied strings. In the affected releases, one or more of these input paths fail to sanitize or contextually encode script-bearing content before storing and rendering it back to the browser.
The result is a stored XSS condition. An authenticated administrator submits input containing HTML or JavaScript payloads, which the server persists and later renders inside the management UI. When a second privileged user views the affected page, their browser executes the payload under the ISE origin.
Because script executes with the same trust as the target user, an attacker can read Document Object Model (DOM) content, exfiltrate session identifiers, invoke authenticated API calls on behalf of the victim, or pivot into other ISE-managed workflows. Exploitation requires user interaction to load the affected page.
Root Cause
The vulnerability is caused by insufficient input validation and output encoding in the ISE web-based management interface. Untrusted administrator-supplied strings reach an HTML rendering context without being neutralized, matching the pattern described in [CWE-80]. The scope change flag in the CVSS vector indicates that script executing under the ISE origin can affect resources beyond the vulnerable component itself.
Attack Vector
Exploitation requires valid administrative credentials on the ISE instance and a second user who loads the injected page. The attacker authenticates to the web interface, injects a malicious payload into a vulnerable input field, and waits for another operator to visit the affected view. See the Cisco Security Advisory for ISE Stored XSS for vendor-confirmed details.
No public proof-of-concept exploit code is available for CVE-2025-20267 at the time of publication.
Detection Methods for CVE-2025-20267
Indicators of Compromise
- Administrator-submitted configuration objects containing HTML tags, JavaScript event handlers, or <script> elements in string fields.
- Unexpected outbound requests from ISE administrator browsers to attacker-controlled domains following interface navigation.
- Anomalous administrative API activity performed under a session ID that recently loaded the affected page.
Detection Strategies
- Inspect ISE audit logs for configuration writes containing suspicious character sequences such as <script, onerror=, or javascript: in operator-supplied fields.
- Correlate administrator logins with subsequent unusual API calls that appear to originate from the browser rather than from the operator's normal workflow.
- Monitor browser-side Content Security Policy (CSP) violation reports, if enabled, for the ISE origin.
Monitoring Recommendations
- Forward ISE administrative audit logs and web access logs to a centralized analytics platform for retention and query.
- Alert on privileged account creation, policy modification, or credential export events that immediately follow a session interacting with newly modified UI objects.
- Track lateral use of administrator sessions across the ISE cluster, including changes originating from unexpected source addresses.
How to Mitigate CVE-2025-20267
Immediate Actions Required
- Apply the fixed Cisco ISE release identified in the vendor advisory to all Policy Administration Nodes.
- Restrict access to the ISE web management interface to a dedicated administrative network segment or jump host.
- Review the roster of accounts with administrative privileges and remove any that are no longer required.
- Rotate administrator credentials and invalidate active sessions after patching.
Patch Information
Cisco has published fixed software for affected 3.2, 3.3, and 3.4 trains. Refer to the Cisco Security Advisory: ISE Stored XSS for the fixed release matrix and upgrade guidance. Cisco does not list workarounds that fully address this issue; upgrading is the recommended remediation.
Workarounds
- Limit administrative access to trusted operators and enforce multi-factor authentication for all ISE administrator accounts.
- Use separate browsers or browser profiles dedicated to ISE administration to reduce cross-application session exposure.
- Enforce short administrative session lifetimes and require re-authentication for sensitive operations.
- Segment the ISE management plane from general-purpose networks using firewall access control lists.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
