PT-2018-27: Arbitrary Command Execution in Cisco Secure ACS

Vulnerable product

Cisco ACS
Version: and earlier


Severity level

Severity level: High
Impact: Remote command execution
Access Vector: Remote

CVSS v3:
Base Score: 9.8
Vector: (AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H)

CVE: CVE-2018-0253

Vulnerability description

The specialists of the Positive Research center have detected an Arbitrary Command Execution vulnerability in Cisco Secure ACS.

A vulnerability in Cisco Secure Access Control System (ACS), due to insufficient validation of the Action Message Format (AMF) protocol, allows unauthenticated, remote attackers to execute arbitrary commands on the ACS device by sending a crafted AMF message that contains malicious code.

How to fix

Use vendor's advisory:

Advisory status

01.06.2017 - Vendor gets vulnerability details
02.05.2018 - Vendor releases fixed version and details
11.12.2018 - Public disclosure


The vulnerability was detected by Mikhail Klyuchnikov, Yury Aleynov, Positive Research Center (Positive Technologies Company)


Reports on the vulnerabilities previously discovered by Positive Research:

About Positive Technologies

Positive Technologies is a leading digital security firm with over 15 years of experience in 360° protection of critical IT systems against the most advanced cyberthreats. State-of-the-art solutions are developed at the company's research center—one of the largest in Europe. Positive Technologies experts have helped to identify and fix over 250 zero-day vulnerabilities in products from Cisco, Google, Honeywell, Huawei, Microsoft, Oracle, SAP, Schneider Electric, Siemens, and others, earning a reputation for world-class expertise in protection of devices and infrastructures at all scales from ATMs to nuclear power stations. Findings by Positive Technologies researchers are used for updating the MaxPatrol knowledge base and for development of security solutions including PT Application Firewall, PT Application Inspector, MaxPatrol. These products allow securing web applications, evaluating network protection, blocking attacks in real time, ensuring compliance with industry and national standards, and training security specialists. Positive Technologies is the organizer of the annual Positive Hack Days international forum and security competition.