CVE-2022-22806: Schneider Electric UPS Auth Bypass Flaw

CVE-2022-22806 Overview

CVE-2022-22806 is an Authentication Bypass by Capture-replay vulnerability (CWE-294) affecting Schneider Electric SmartConnect UPS devices. This vulnerability allows an unauthenticated attacker to establish a connection to the UPS by sending a malformed connection request. The flaw exists in the TLS implementation of the affected firmware, enabling attackers to bypass authentication mechanisms and gain unauthorized access to critical power infrastructure devices.

Critical Impact

Successful exploitation allows unauthenticated remote attackers to gain complete control over UPS devices, potentially causing power disruption to critical systems, data centers, and industrial environments.

Affected Products

• Schneider Electric SMT Series (ID=1015) - UPS firmware 04.5 and prior
• Schneider Electric SMC Series (ID=1018) - UPS firmware 04.2 and prior
• Schneider Electric SMTL Series (ID=1026) - UPS firmware 02.9 and prior
• Schneider Electric SCL Series (ID=1029, 1030, 1036) - UPS firmware 02.5 and prior
• Schneider Electric SCL Series (ID=1037) - UPS firmware 03.1 and prior
• Schneider Electric SMX Series (ID=1031) - UPS firmware 03.1 and prior

Discovery Timeline

• March 9, 2022 - CVE-2022-22806 published to NVD
• November 21, 2024 - Last updated in NVD database

Technical Details for CVE-2022-22806

Vulnerability Analysis

This vulnerability stems from improper handling of TLS handshake sequences in Schneider Electric SmartConnect UPS devices. The authentication bypass occurs during the connection establishment phase, where the firmware fails to properly validate the authenticity of connection requests. An attacker can exploit this weakness by capturing and replaying authentication sequences or by sending specially crafted malformed connection packets that circumvent the normal authentication flow.

The vulnerability is particularly concerning because it targets critical infrastructure devices. UPS systems are fundamental components in data centers, hospitals, industrial control systems, and other environments where power continuity is essential. Unauthorized access to these devices could allow attackers to disrupt power supply, modify device configurations, or use the compromised device as a pivot point for further network intrusion.

Root Cause

The root cause of CVE-2022-22806 lies in the improper implementation of TLS session handling within the SmartConnect firmware. The affected devices fail to implement adequate protections against capture-replay attacks during the authentication phase. Specifically, the firmware does not properly validate session tokens or implement sufficient anti-replay mechanisms such as nonces or timestamps, allowing previously captured authentication sequences to be reused by attackers.

Attack Vector

The attack vector is network-based and can be executed remotely without requiring any prior authentication or user interaction. An attacker positioned on the same network as the vulnerable UPS device, or with network access to the device's management interface, can:

1. Capture legitimate TLS handshake traffic between authorized users and the UPS
2. Replay the captured authentication sequence to establish an unauthorized session
3. Alternatively, craft malformed connection requests that exploit the authentication validation weakness

The attack requires no privileges and has low complexity, making it accessible to a wide range of threat actors. Once authentication is bypassed, the attacker gains full access to UPS management functions.

Detection Methods for CVE-2022-22806

Indicators of Compromise

• Unusual or unexpected connections to UPS management interfaces from unauthorized IP addresses
• Multiple rapid authentication attempts or connection requests to SmartConnect UPS devices
• Network traffic showing replayed TLS handshake patterns or malformed connection sequences
• Unexpected configuration changes or power state modifications on UPS devices

Detection Strategies

• Deploy network monitoring to detect anomalous traffic patterns to UPS management ports
• Implement intrusion detection rules to identify potential capture-replay attack signatures
• Monitor authentication logs on network infrastructure for connections to UPS devices from unexpected sources
• Use network segmentation monitoring to detect lateral movement attempts toward OT/ICS network segments

Monitoring Recommendations

• Enable detailed logging on network devices and firewalls protecting UPS infrastructure
• Implement real-time alerting for any administrative access to UPS devices
• Regularly audit network connections to critical infrastructure devices including UPS systems
• Deploy SentinelOne Singularity platform with network visibility to detect suspicious connection patterns to OT devices

How to Mitigate CVE-2022-22806

Immediate Actions Required

• Isolate affected SmartConnect UPS devices from untrusted networks immediately
• Implement strict network segmentation to limit access to UPS management interfaces
• Apply firewall rules to restrict management interface access to authorized IP addresses only
• Review access logs for any signs of unauthorized access or exploitation attempts

Patch Information

Schneider Electric has released firmware updates to address this vulnerability. Organizations should obtain the latest firmware versions from the Schneider Electric Security Advisory (SEVD-2022-067-02) and apply updates to all affected SmartConnect UPS devices. The advisory contains specific firmware versions and download links for each affected product series.

Workarounds

• Disable remote management access to UPS devices if not operationally required
• Place UPS management interfaces on isolated management VLANs with strict access controls
• Implement VPN or jump server requirements for any remote administrative access
• Deploy additional network-based authentication mechanisms such as 802.1X for devices accessing UPS management networks

# Network segmentation example - restrict UPS management access
# Example iptables rules to limit access to UPS management interface
iptables -A INPUT -p tcp --dport 443 -s 10.10.10.0/24 -j ACCEPT
iptables -A INPUT -p tcp --dport 443 -j DROP

# Restrict access to management VLAN
iptables -A FORWARD -d 192.168.100.0/24 -s 10.0.0.0/8 -j DROP
iptables -A FORWARD -d 192.168.100.0/24 -s 172.16.0.0/12 -j DROP