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CVE-2025-20281: Cisco Identity Services Engine Injection Vulnerability

CVE-2025-20281 is rated critical with a CVSS v3.1 base score of 10.0 and affects Cisco Identity Services Engine. Per its scoring, it can be exploited over the network, without authentication, without any user interaction. The scored impact on confidentiality, integrity and availability is the highest available. CISA added it to its Known Exploited Vulnerabilities catalog on 2025-07-28, which means exploitation in the wild has been observed.

Vulnerability description

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.

Severity breakdown

CVSS v3.1 10.0: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H

  • Attack vector: Network. Exploitable remotely over the network, with no need for local or physical access.
  • Attack complexity: Low. No special conditions; the attack can be repeated reliably.
  • Privileges required: None. No account or prior access is needed.
  • User interaction: None. No action from any user is needed.
  • Scope: Changed. Impact reaches beyond the vulnerable component to other resources.
  • Confidentiality impact: High. Total loss of confidentiality; sensitive data can be fully disclosed.
  • Integrity impact: High. Total loss of integrity; data or system state can be fully modified.
  • Availability impact: High. Total loss of availability; the component can be shut down.

Underlying weakness

CWE-74: Improper Neutralization of Special Elements in Output Used by a Downstream Component

The product constructs all or part of a command, data structure, or record using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify how it is parsed or interpreted when it is sent to a downstream component.

Affected products

  • Cisco Identity Services Engine: 3.3.0; 3.3.0 patch1; 3.3.0 patch2; 3.3.0 patch3; 3.3.0 patch4; 3.3.0 patch5; 3.3.0 patch6; 3.4.0; 3.4.0 patch1
  • Cisco Identity Services Engine Passive Identity Connector: 3.3.0; 3.3.0 patch1; 3.3.0 patch2; 3.3.0 patch3; 3.3.0 patch4; 3.3.0 patch5; 3.3.0 patch6; 3.4.0; 3.4.0 patch1

References