Urgent Security Alert: Critical Cisco ISE Flaw Actively Exploited in Attacks
A critical vulnerability in Cisco’s Identity Services Engine (ISE) is being actively exploited by attackers, enabling them to gain complete control over affected networks. If your organization uses Cisco ISE, immediate action is required to prevent a potentially devastating breach.
Cisco ISE is a foundational network security product that acts as a central gatekeeper, controlling who and what can access your corporate network. A compromise of this system can provide attackers with a powerful foothold to move laterally, deploy ransomware, and exfiltrate sensitive data.
The vulnerability at the heart of these attacks is tracked as CVE-2022-20825, a critical remote code execution (RCE) flaw that requires no authentication to exploit.
Understanding the Threat: CVE-2022-20825
This vulnerability exists within the RADIUS service component of Cisco ISE. By sending a specially crafted RADIUS request to an affected device, a remote attacker can trigger a buffer overflow. This allows them to execute arbitrary code on the underlying operating system with the privileges of the ISE process.
Here’s why this is so dangerous:
- Remote & Unauthenticated: The attacker does not need to be on your local network or have any login credentials. They can launch the attack from anywhere on the internet if the device is exposed.
- Total Control: Successful exploitation grants the attacker remote code execution, meaning they can run any command they want on your ISE server.
- Gateway to the Network: Since ISE manages network access policies, a compromised server gives attackers the “keys to the kingdom,” allowing them to manipulate access rules, create rogue accounts, and disable security controls.
The vulnerability specifically impacts Cisco ISE versions 3.1 and 3.2. Organizations running these versions are at high risk and should consider themselves prime targets.
Active Exploitation Confirmed
Security researchers have confirmed that threat actors are actively scanning for and exploiting this vulnerability in the wild. These are not theoretical attacks; they are happening now. Attackers are using this entry point to establish persistent access and deploy custom malware designed to steal credentials and maintain control over the compromised network.
Once they gain initial access via the ISE flaw, attackers can:
- Disable security logging to cover their tracks.
- Create new administrator accounts for persistent access.
- Modify network access policies to allow their own devices onto the network.
- Move laterally to other critical servers, such as domain controllers and file servers.
How to Protect Your Network: Actionable Security Steps
Protecting your organization requires immediate and decisive action. Follow these steps to mitigate the threat from CVE-2022-20825.
1. Identify All Affected Devices
Your first step is to inventory all Cisco ISE instances within your environment. Verify the software version of each appliance. If you are running any version of Cisco ISE 3.1 or 3.2, you must proceed with patching immediately.
2. Apply Security Patches Urgently
Cisco has released software updates that address this critical vulnerability. Patching is the only definitive way to remediate this threat. Do not delay applying these updates. Prioritize patching for any ISE servers that are exposed to the internet, followed by internal-facing servers.
3. Implement Mitigations and Harden Your Systems
If you cannot patch immediately, you must implement temporary workarounds to reduce your attack surface. While not a substitute for patching, these measures can provide a layer of defense:
- Restrict Access with ACLs: Configure Access Control Lists (ACLs) on your firewalls and routers to strictly limit which IP addresses can communicate with your ISE appliances on the RADIUS port (UDP/1812). Ideally, only trusted RADIUS clients (like your wireless controllers and switches) should be able to reach this port.
- Monitor for Suspicious Activity: Actively monitor logs for unusual or malformed RADIUS requests. Check the ISE server for any unexpected running processes, new files, or unauthorized configuration changes.
4. Hunt for Signs of Compromise
Given that this vulnerability is being actively exploited, it is crucial to assume you may have already been targeted. Your security team should proactively hunt for indicators of compromise (IoCs) related to this threat. Review historical logs and system activity for anything that appears anomalous, especially around the time the vulnerability was disclosed.
Staying vigilant is key. This incident underscores the importance of maintaining a robust patch management program and a defense-in-depth security posture, especially for critical infrastructure like network access control systems.
Source: https://www.bleepingcomputer.com/news/security/cisco-maximum-severity-ise-rce-flaws-now-exploited-in-attacks/
