CVE-2025-20337
About
A vulnerability 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 this vulnerability.
This vulnerability is due to insufficient validation of user-supplied input. An attacker could exploit this vulnerability by submitting a crafted API request. A successful exploit could allow the attacker to obtain root privileges on an affected device.
Rainforest analyst review
A specific API in Cisco Identity Services Engine (ISE) and the ISE Passive Identity Connector (ISE-PIC) insufficiently validates user-supplied input. An unauthenticated remote attacker who submits a crafted request to that API can inject data the application mishandles, resulting in arbitrary code execution on the underlying operating system as root. No valid credentials are required, and the outcome is complete, highest-privilege control of the appliance.
ISE is Cisco's network access control and policy engine: it decides which users and devices get onto the network and enforces segmentation, so root on an ISE node is a commanding position over network access across the enterprise. This was one of several critical ISE API bugs disclosed together in mid-2025, carrying a CVSS 10, and Cisco later confirmed active exploitation attempts against these flaws, which drove it onto CISA's KEV list. Apply the fixed Cisco software releases without delay rather than relying on interim hot patches for the full chain, keep the ISE administrative and API interfaces off untrusted networks, and inspect appliances for signs of root-level compromise given the severity and confirmed targeting.
References
Related CVEs
Frequently asked questions
What is CVE-2025-20337?
A vulnerability 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 this vulnerability. This vulnerability is due to insufficient validation of user-supplied input.
How severe is CVE-2025-20337?
CVE-2025-20337 carries a CVSS 3.1 base score of 10, rated critical. On the Rainforest Risk Index — which weighs the severity alongside how easy the flaw is to reach and how broad its impact is — it scores 100 out of 100, in the critical band.
How is CVE-2025-20337 exploited?
According to the CVSS vector (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H): attack vector Network, attack complexity Low, privileges required None, user interaction None. Impact on confidentiality High, integrity High and availability High.
Which products are affected by CVE-2025-20337?
Public advisories list the following as affected: identity services engine, identity services engine passive identity connector. Check the references on this page for the exact versions each vendor confirms.
How do I fix CVE-2025-20337?
Apply the fix the vendor published — the references on this page link to the primary advisories and patches. When patching can't happen right away, reduce the exposure of the affected component and watch it for exploitation attempts. Rainforest customers see this vulnerability correlated to their own assets and prioritized by real exposure, not by score alone.
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