CVE-2020-3225 Overview
Multiple vulnerabilities in the implementation of the Common Industrial Protocol (CIP) feature of Cisco IOS Software and Cisco IOS XE Software could allow an unauthenticated, remote attacker to cause an affected device to reload, resulting in a denial of service (DoS) condition. The vulnerabilities stem from insufficient input processing of CIP traffic, which is widely used in industrial automation environments to facilitate communication between control systems and devices.
An attacker could exploit these vulnerabilities by sending specially crafted CIP traffic to be processed by an affected device. A successful exploit could allow the attacker to cause the affected device to reload, resulting in a denial of service condition that could disrupt critical industrial operations and network infrastructure.
Critical Impact
Remote unauthenticated attackers can cause network device reloads via malformed CIP traffic, potentially disrupting industrial control systems and critical infrastructure operations.
Affected Products
- Cisco IOS (multiple versions including 12.2.x, 15.0.x, 15.2.x, and 15.3.x releases)
- Cisco IOS XE (versions including 3.3.x, 3.6.x, 3.8.x, 3.10.x, 16.3.x through 16.12.x)
- Devices with the Common Industrial Protocol (CIP) feature enabled
Discovery Timeline
- June 3, 2020 - CVE-2020-3225 published to NVD
- November 21, 2024 - Last updated in NVD database
Technical Details for CVE-2020-3225
Vulnerability Analysis
This vulnerability exists within the Common Industrial Protocol (CIP) implementation in Cisco IOS and IOS XE Software. CIP is an industrial protocol used for real-time control and information exchange in automation systems, commonly found in manufacturing, process control, and critical infrastructure environments.
The vulnerability allows remote attackers to cause a denial of service condition by sending malformed CIP packets to affected devices. When the vulnerable device processes these specially crafted packets, it fails to properly validate the input, leading to a device reload. This can result in significant downtime for network infrastructure supporting industrial operations.
The scope of this vulnerability extends beyond the vulnerable component itself, as a successful attack can impact other systems dependent on the affected network device for connectivity and communication.
Root Cause
The root cause is classified as CWE-20: Improper Input Validation. The CIP traffic processing routines in Cisco IOS and IOS XE fail to adequately validate incoming CIP packets before processing them. This insufficient input validation allows malformed or unexpected data to be processed in ways that cause the device to enter an unstable state, ultimately triggering a reload.
The lack of proper boundary checking and input sanitization in the CIP protocol handler permits attackers to craft packets that exploit this weakness without requiring authentication or special privileges.
Attack Vector
The attack can be executed remotely over the network without authentication. An attacker with network access to an affected device's CIP-enabled interface can send malicious traffic to trigger the vulnerability. The attack has low complexity and requires no user interaction, making it highly exploitable in exposed environments.
The exploitation process involves:
- Identifying a target device running vulnerable Cisco IOS or IOS XE with CIP enabled
- Crafting malformed CIP traffic designed to trigger improper input handling
- Sending the crafted packets to the target device's CIP interface
- The vulnerable device fails to properly process the malformed input and reloads
The attack can be repeated to cause persistent denial of service, preventing the affected device from maintaining stable operations.
Detection Methods for CVE-2020-3225
Indicators of Compromise
- Unexpected device reloads or crashes on Cisco IOS/IOS XE devices with CIP enabled
- Abnormal or malformed CIP traffic patterns on UDP/TCP port 44818 or TCP port 2222
- Crash dumps or syslogs indicating CIP-related processing failures
- Multiple consecutive reloads without apparent hardware failure
Detection Strategies
- Deploy network intrusion detection systems (IDS) with signatures for malformed CIP traffic patterns
- Monitor syslog messages from Cisco devices for unexpected reload events and CIP-related errors
- Implement deep packet inspection for CIP protocol traffic to identify anomalous packets
- Correlate device reload events with incoming CIP traffic patterns to identify potential attacks
Monitoring Recommendations
- Enable SNMP traps for device reload events on all Cisco IOS/IOS XE devices
- Configure centralized logging to capture and analyze device crash events in real-time
- Implement network traffic analysis for CIP protocol communications to baseline normal behavior
- Set up alerting for unexpected device state changes and service interruptions
How to Mitigate CVE-2020-3225
Immediate Actions Required
- Apply the security patches provided by Cisco as detailed in the official security advisory
- If patching is not immediately possible, disable the CIP feature on affected devices if not operationally required
- Implement access control lists (ACLs) to restrict CIP traffic to trusted sources only
- Segment networks to isolate industrial control systems from untrusted network segments
Patch Information
Cisco has released software updates that address this vulnerability. Organizations should consult the Cisco Security Advisory for specific fixed software versions applicable to their deployment. The advisory provides detailed information about affected releases and recommended upgrade paths.
Customers should upgrade to a fixed software release using the Cisco Software Checker tool or by consulting with Cisco TAC to determine the appropriate fixed version for their environment.
Workarounds
- Disable the CIP feature on devices where it is not required for operations using the no cip enable command
- Implement infrastructure ACLs to limit CIP traffic to only authorized endpoints and networks
- Deploy network segmentation to isolate CIP-enabled devices from untrusted network segments
- Consider using a firewall or IPS to filter and inspect CIP traffic before it reaches vulnerable devices
# Configuration example - Disable CIP feature if not required
configure terminal
no cip enable
end
write memory
# Alternative - Restrict CIP traffic with ACL
configure terminal
ip access-list extended RESTRICT-CIP
permit udp host <trusted-source> any eq 44818
permit tcp host <trusted-source> any eq 44818
permit tcp host <trusted-source> any eq 2222
deny udp any any eq 44818
deny tcp any any eq 44818
deny tcp any any eq 2222
permit ip any any
exit
interface <interface-name>
ip access-group RESTRICT-CIP in
end
write memory
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
