CVE-2025-20284: Cisco Identity Services Engine RCE Flaw

CVE-2025-20284 Overview

CVE-2025-20284 is a high-severity command injection vulnerability affecting Cisco Identity Services Engine (ISE) and Cisco ISE Passive Identity Connector (ISE-PIC). The flaw resides in a specific API endpoint that fails to properly validate user-supplied input. An authenticated remote attacker with valid high-privileged credentials can submit a crafted API request to execute arbitrary commands as root on the underlying operating system. The vulnerability is tracked under [CWE-74] (Improper Neutralization of Special Elements in Output Used by a Downstream Component) and carries an EPSS probability in the 95th percentile, indicating elevated exploitation likelihood relative to other published CVEs.

Critical Impact
Successful exploitation results in full root-level code execution on Cisco ISE appliances, exposing identity and access control infrastructure to complete compromise.

Affected Products

Cisco Identity Services Engine 3.3 (including patches 1 through 6)
Cisco Identity Services Engine 3.4 (including patch 1)
Cisco Identity Services Engine Passive Identity Connector (ISE-PIC) 3.3 and 3.4

Discovery Timeline

2025-07-16 - CVE-2025-20284 published to the National Vulnerability Database
2025-07-22 - Last updated in NVD database

Technical Details for CVE-2025-20284

Vulnerability Analysis

The vulnerability stems from insufficient validation of user-supplied input in a specific API of Cisco ISE and Cisco ISE-PIC. Cisco ISE serves as a centralized policy engine for network access control, profiling, posture assessment, and guest services in enterprise environments. Because the API executes downstream commands with root privileges, malicious input that escapes the expected parameter context can be interpreted as operating system commands. This pattern aligns with [CWE-74] injection weaknesses, where untrusted input flows into a sensitive interpreter without neutralization.

A successful exploit grants the attacker direct control over the appliance hosting the identity infrastructure. From that position, an attacker can manipulate authentication policies, exfiltrate credential material, pivot to managed endpoints, or disable enforcement entirely.

Root Cause

The root cause is improper neutralization of special elements in input supplied to an authenticated API endpoint. The API forwards attacker-controlled values into a process invocation that executes under the root account, allowing command separators or shell metacharacters to break out of intended argument boundaries.

Attack Vector

The attack vector is network-based and requires valid high-privileged credentials on the target ISE deployment. An attacker authenticates to the management plane and issues a crafted HTTPS API request containing malicious payload data. The exploit requires no user interaction and operates at low complexity once credentials are obtained, making credential theft or insider misuse the primary precondition.

No public proof-of-concept code or in-the-wild exploitation has been confirmed at the time of publication. Refer to the Cisco Security Advisory cisco-sa-ise-multi-3VpsXOxO for additional vendor detail.

Detection Methods for CVE-2025-20284

Indicators of Compromise

Unexpected processes spawned by the ISE application service running as root, particularly shells or interpreters launched from API worker contexts.
API requests to administrative endpoints containing shell metacharacters such as ;, |, `, $(, or newline-encoded sequences in parameter values.
New or modified files in writable system directories on the ISE appliance shortly after authenticated API activity.
Outbound network connections originating from the ISE appliance to unfamiliar destinations following high-privilege API calls.

Detection Strategies

Review Cisco ISE administrative audit logs and API access logs for crafted payloads in parameter values originating from high-privilege accounts.
Correlate administrator API sessions with downstream process execution and file system changes on the appliance.
Alert on authentication events for high-privileged ISE accounts from atypical source IPs, time windows, or geographies.

Monitoring Recommendations

Forward ISE syslog, audit, and operations logs to a centralized analytics platform and retain them for forensic review.
Monitor administrative accounts for privilege changes, password resets, and API token issuance.
Track configuration drift on ISE nodes, including unexpected services, scheduled tasks, or modifications to policy sets.

How to Mitigate CVE-2025-20284

Immediate Actions Required

Apply the fixed software release published in the Cisco Security Advisory cisco-sa-ise-multi-3VpsXOxO for all ISE and ISE-PIC deployments.
Inventory ISE 3.3 and 3.4 nodes, including patches 1 through 6 on 3.3 and patch 1 on 3.4, and prioritize patching.
Rotate credentials for all high-privileged ISE administrators and audit recent administrative API activity for signs of misuse.
Restrict management plane access to dedicated administrative networks and trusted jump hosts.

Patch Information

Cisco has released fixed software for both Cisco Identity Services Engine and Cisco ISE Passive Identity Connector. Customers should consult the vendor advisory for the specific fixed version that corresponds to their currently installed train and apply the upgrade through standard ISE patching procedures.

Workarounds

No vendor-confirmed workaround removes the vulnerability; patching is the authoritative remediation.
Enforce least privilege for ISE administrative accounts and require multi-factor authentication on the management interface.
Limit API exposure by restricting administrative endpoints to allow-listed source addresses at the network and appliance level.

bash

# Example: restrict ISE admin/API access to a trusted management subnet
# Apply on the upstream firewall or ACL controlling the ISE management VLAN
permit tcp 10.10.50.0/24 host <ise-admin-ip> eq 443
deny   tcp any host <ise-admin-ip> eq 443