What is CVE-2025-20337?

CVE-2025-20337 is a critical-severity vulnerability in Cisco Identity Services Engine Software, classified under Improper Neutralization of Special Elements in Output Used by a Downstream Component (Injection). CVSS score: 10.0/10. Published 2025-07-16.

How severe is CVE-2025-20337?

Critical severity. CVSS v3 base score is 10.0 out of 10.

Is CVE-2025-20337 known to be exploited?

Yes. CVE-2025-20337 is listed in the CISA Known Exploited Vulnerabilities catalog (added 2025-07-28), indicating it is being actively exploited. 7 public proof-of-concept repositories are indexed.

Vulnerability in Cisco Identity Services Engine Software

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. 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.

EPSS: 0.673 (99.2th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 10.0 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H.

Affected products

Cisco Identity Services Engine Software — versions 3.3.0, 3.3 Patch 2, 3.3 Patch 1
Cisco Ise Passive Identity Connector — versions 3.2.0, 3.1.0, 3.3.0
Cisco Identity_services_engine — versions 3.3.0, 3.4.0
Cisco Identity_services_engine_passive_identity_connector — versions 3.3.0, 3.4.0

Weakness classification (CWE)

CWE-74 — Improper Neutralization of Special Elements in Output Used by a Downstream Component (Injection)

CISA KEV (Known Exploited Vulnerabilities)

This CVE is on the CISA KEV catalog, added on 2025-07-28. CISA KEV inclusion means CISA has confirmed in-the-wild exploitation; US federal agencies are required to remediate within a published due date.

BOD 22-01 due date: 2025-08-18.

Required action: Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.

Public proof-of-concept exploits

References

psirt@cisco.com (Vendor Advisory)
134c704f-9b21-4f2e-91b3-4a467353bcc0 (US Government Resource)

Frequently asked questions

What is CVE-2025-20337?: CVE-2025-20337 is a critical-severity vulnerability in Cisco Identity Services Engine Software, classified under Improper Neutralization of Special Elements in Output Used by a Downstream Component (Injection). CVSS score: 10.0/10. Published 2025-07-16.
How severe is CVE-2025-20337?: Critical severity. CVSS v3 base score is 10.0 out of 10.
Is CVE-2025-20337 known to be exploited?: Yes. CVE-2025-20337 is listed in the CISA Known Exploited Vulnerabilities catalog (added 2025-07-28), indicating it is being actively exploited. 7 public proof-of-concept repositories are indexed.