CVE-2025-20337
Cisco Identity Services Engine Injection Vulnerability
Cisco Identity Services Engine
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.
Exploitation status
CISA Known Exploited Vulnerabilities
Listed by CISA on 28 July 2025. US federal agencies were required to remediate it by 18 August 2025.
EPSS — exploitation probability
FIRST puts the probability of exploitation activity in the next 30 days at 68%, which is higher than 99.3% of all scored vulnerabilities. EPSS is a forecast of activity, not a measure of severity, and it is rescored daily.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
Frequently asked questions
Is CVE-2025-20337 being exploited by ransomware groups?
No ransomware group in this database is currently recorded as exploiting CVE-2025-20337.
What does CVE-2025-20337 affect?
CVE-2025-20337 affects Cisco Identity Services Engine. 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.
How severe is CVE-2025-20337?
CVE-2025-20337 is rated CRITICAL with a CVSS base score of 10. EPSS puts the probability of exploitation in the next 30 days at 68%, higher than 99.3% of all scored vulnerabilities. It is listed in the CISA Known Exploited Vulnerabilities catalog, with a federal remediation deadline of 18 August 2025.
How should organisations respond to CVE-2025-20337?
Apply the vendor patch for Cisco Identity Services Engine as the first priority, and treat any internet-facing instance as the most urgent. Because this vulnerability is associated with ransomware activity, also review whether the affected systems were reachable before patching, rather than assuming that patching alone closes the incident.