CVE-2025-20124 - Arbitrary Command Execution in Cisco ISE API due to Insecure Deserialization

A newly discovered vulnerability (CVE-2025-20124) in the Cisco Identity Services Engine (ISE) software makes it possible for an authenticated, remote attacker to execute arbitrary commands as the root user on an affected device. The issue lies within insecure deserialization of user-supplied Java byte streams by the affected software. An attacker could exploit this vulnerability by sending a crafted serialized Java object to an affected API. This could lead to code execution at administrator level access on the device.

The Cisco ISE platform is a unified, context-aware network access control solution that enforces security policies by collecting, analyzing, and sharing network-wide contextual information. The current vulnerability exposes an API that can be exploited by attackers with valid read-only administrative credentials.

Exploit Details

To exploit this vulnerability, an attacker would need read-only administrative credentials. A successful exploit would enable the attacker to elevate their privileges to root and execute arbitrary commands on the device.

The affected API allows users to interact with the system remotely to carry out certain tasks. An attacker could gain access to this API by sending a crafted serialized Java object that takes advantage of insecure deserialization. This compromises the integrity and security of the system, gaining unauthorized control over the device.

Here is an example of an exploit using Python

import requests

payload = "<INSERT_SERIALZIED_JAVA_OBJECT_HERE>"
headers = {
    "Content-Type": "application/octet-stream",
    "Authorization": "Basic <INSERT_Authorization_HERE>",
}

url = "https://<ISE_IP_ADDRESS>/<API_PATH>";

response = requests.post(url, data=payload, headers=headers)

if response.status_code == 200:
    print(f"Vulnerability exploited. Response: {response.text}")
else:
    print(f"Exploit failed. Response: {response.text}")

Original References

- https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-ise-dos-AJm4ytps
- https://nvd.nist.gov/vuln/detail/CVE-2025-20124

Mitigation

Cisco has released a software update that addresses this vulnerability. It is recommended to apply the patch immediately to protect your environment. For more information on the patches and workarounds, organizations should consult their respective vendor support channels.

Conclusion

The vulnerability in the Cisco Identity Services Engine (CVE-2025-20124) allows an attacker to execute arbitrary commands on the affected device. This is done by exploiting insecure deserialization in the API. To protect against this vulnerability, it is crucial to update your software and implement security best practices to minimize the chances of attackers gaining unauthorized control over your devices.

Timeline

Published on: 02/05/2025 17:15:22 UTC