Cisco Identity Services Engine Unauthenticated Remote Code Execution Vulnerabilities

TL;DR 📌

• Multiple vulnerabilities in Cisco Identity Services Engine (ISE) and Cisco ISE Passive Identity Connector (ISE-PIC) could allow an unauthenticated, remote attacker to issue commands on the underlying operating system as the root user. For more information about these vulnerabilities, see the Details ["#details"] section of this advisory. Cisco has released software updates that address these vulnerabilities. There are no workarounds…
• No fixed release listed yet; apply mitigations and monitor.
• Workarounds are documented in the advisory.
• CVEs: CVE-2025-20282, CVE-2025-20281, CVE-2025-20337.

What happened 🕵️‍♂️

The vulnerabilities are not dependent on one another. Exploitation of one of the vulnerabilities is not required to exploit another vulnerability. In addition, a software release that is affected by one of the vulnerabilities may not be affected by the other vulnerabilities.

Details about the vulnerabilities are as follows:

CVE-2025-20281 and CVE-2025-20337: Cisco ISE API Unauthenticated Remote Code Execution Vulnerabilities

Multiple vulnerabilities in a specific API of Cisco ISE and Cisco ISE-PIC could allow an unauthenticated, remote attacker to execute arbitrary code on the underlying operating system as root. The attacker does not require any valid credentials to exploit these vulnerabilities.

These vulnerabilities are due to insufficient validation of user-supplied input. An attacker could exploit these vulnerabilities by submitting a crafted API request. A successful exploit could allow the attacker to obtain root privileges on an affected device.

Cisco has released software updates that address these vulnerabilities. There are no workarounds that address these vulnerabilities.

Bug ID(s): CSCwo99449 [“https://bst.cloudapps.cisco.com/bugsearch/bug/CSCwo99449”] and CSCwp02814 [“https://bst.cloudapps.cisco.com/bugsearch/bug/CSCwp02814”] CVE ID: CVE-2025-20281, CVE-2025-20337 Security Impact Rating (SIR): Critical CVSS Base Score: 10.0 CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H

CVE-2025-20282: Cisco ISE API Unauthenticated Remote Code Execution Vulnerability

A vulnerability in an internal API of Cisco ISE and Cisco ISE-PIC could allow an unauthenticated, remote attacker to upload arbitrary files to an affected device and then execute those files on the underlying operating system as root.

This vulnerability is due a lack of file validation checks that would prevent uploaded files from being placed in privileged directories on an affected system. An attacker could exploit this vulnerability by uploading a crafted file to the affected device. A successful exploit could allow the attacker to store malicious files on the affected system and then execute arbitrary code or obtain root privileges on the system.

Cisco has released software updates that address this vulnerability. There are no workarounds that address this vulnerability. Bug ID(s): CSCwp02821 [“https://bst.cloudapps.cisco.com/bugsearch/bug/CSCwp02821”] CVE ID: CVE-2025-20282 Security Impact Rating (SIR): Critical CVSS Base Score: 10.0 CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H

Affected products 🖥️

CVE-2025-20281 and CVE-2025-20337: These vulnerabilities affect Cisco ISE and ISE-PIC releases 3.3 and 3.4, regardless of device configuration. These vulnerabilities do not affect Cisco ISE and ISE-PIC Release 3.2 or earlier.

CVE-2025-20282: This vulnerability affects only Cisco ISE and ISE-PIC Release 3.4, regardless of device configuration. This vulnerability does not affect Cisco ISE and ISE-PIC Release 3.3 or earlier.

Fixed software 🔧

Upgrade to the first fixed release in your train (or later):

Workarounds 🧯

There are no workarounds that address these vulnerabilities.

Risk in context 🎯

Use vendor CVSS for prioritization. Consider exposure and asset criticality.

Fast facts ⚡

• Advisory: cisco-sa-ise-unauth-rce-ZAd2GnJ6
• Initial release: 2025-06-25T16:00:00 UTC
• Last updated: 2025-07-24T23:30:31 UTC

For leadership 🧭

Executive summary. Cisco Identity Services Engine and ISE-PIC on releases 3.3 and 3.4 can be taken over remotely without any credentials, giving an attacker root on the box that controls network access decisions. There are no workarounds, so patching to the fixed releases is the only mitigation and should be treated as urgent given the perfect 10.0 CVSS score across all three CVEs.

Why it matters:

• ISE is the policy engine deciding who and what gets onto the network, so root compromise here can undermine authentication and segmentation controls network-wide.
• CVE-2025-20281 and CVE-2025-20337 hit a specific ISE API with no credential requirement, and affect both 3.3 and 3.4 regardless of how the device is configured.
• CVE-2025-20282 lets an unauthenticated attacker upload files directly into privileged directories on 3.4 systems and execute them as root - a file-upload path with no validation checks.
• Cisco has published no workaround for any of the three flaws, so exposed systems remain at full risk until patched.

Now / Next / Later:

• Now: Identify every Cisco ISE and ISE-PIC deployment running release 3.3 or 3.4 and check its exposure - particularly whether the affected API is reachable from outside trusted management networks.
• Next: Apply 3.3 Patch 7 or 3.4 Patch 2 (whichever matches your train) in the next available change window; releases 3.2 and earlier are not affected and do not need this fix.
• Later: Restrict management-plane and API access to ISE/ISE-PIC to trusted administrative networks only, and build a faster patch-validation path for critical-rated Cisco ISE advisories given the lack of interim workarounds.