CVE-2022-23937: Wind River VxWorks Buffer Overflow Flaw

CVE-2022-23937 Overview

CVE-2022-23937 is an out-of-bounds read vulnerability affecting Wind River VxWorks versions 6.9 and 7.0. The vulnerability occurs when processing a specifically crafted network packet during an IKE (Internet Key Exchange) initial exchange scenario. This flaw can be exploited remotely without authentication to cause a denial of service condition on affected embedded systems.

Critical Impact

Remote attackers can send malicious network packets to trigger an out-of-bounds read, potentially crashing VxWorks-based embedded systems and industrial control devices without requiring any authentication or user interaction.

Affected Products

• Wind River VxWorks 6.9
• Wind River VxWorks 7.0
• Embedded systems and industrial control devices running affected VxWorks versions with IKE enabled

Discovery Timeline

• 2022-03-29 - CVE-2022-23937 published to NVD
• 2024-11-21 - Last updated in NVD database

Technical Details for CVE-2022-23937

Vulnerability Analysis

This vulnerability is classified as CWE-125 (Out-of-Bounds Read), which occurs when the software reads data past the end or before the beginning of an intended buffer. In the context of VxWorks, the flaw manifests during the IKE protocol initial exchange process, which is used for establishing secure VPN connections.

The out-of-bounds read occurs when the IKE implementation fails to properly validate the bounds of incoming packet data during the initial key exchange handshake. When a malformed packet with specific characteristics is received, the VxWorks kernel attempts to read memory outside the allocated buffer, leading to potential system instability or crash.

VxWorks is a real-time operating system (RTOS) widely deployed in critical infrastructure, aerospace, defense, industrial automation, and medical devices. The network-accessible nature of this vulnerability makes it particularly concerning for embedded systems that may be exposed to untrusted networks.

Root Cause

The root cause of CVE-2022-23937 lies in insufficient input validation within the IKE protocol implementation. When processing incoming IKE packets during the initial exchange phase, the affected code does not properly verify that packet field lengths and offsets remain within the bounds of the allocated receive buffer. This allows an attacker to craft packets that cause the parser to read beyond the buffer boundary, triggering undefined behavior.

Attack Vector

The attack can be executed remotely over the network without requiring authentication or user interaction. An attacker needs network access to the target system's IKE service (typically UDP port 500 or 4500). The attack involves sending specially crafted IKE initial exchange packets designed to trigger the out-of-bounds read condition.

The exploitation scenario involves crafting malformed IKE_SA_INIT or equivalent initial exchange packets with manipulated length fields or payload boundaries that cause the VxWorks IKE implementation to read beyond allocated memory. This typically results in a denial of service through system crash or hang, as the RTOS may enter an undefined state when reading invalid memory addresses.

Detection Methods for CVE-2022-23937

Indicators of Compromise

• Unexpected system crashes or reboots on VxWorks-based devices with IKE enabled
• Abnormal IKE traffic patterns on UDP ports 500 and 4500
• Malformed IKE packets with inconsistent length fields in network captures
• System watchdog timeouts or kernel panic events on embedded devices

Detection Strategies

• Deploy network intrusion detection systems (NIDS) with signatures for malformed IKE packets
• Monitor for anomalous UDP traffic patterns targeting ports 500 and 4500
• Implement protocol-aware inspection for IKE/IPsec traffic to detect malformed payloads
• Enable logging and alerting on VxWorks system crashes and watchdog events

Monitoring Recommendations

• Establish baseline network behavior for IKE traffic on critical embedded systems
• Configure SIEM rules to correlate multiple crash events with preceding IKE traffic
• Monitor embedded device availability and implement automated alerting for unexpected reboots
• Capture network traffic to critical VxWorks systems for forensic analysis capability

How to Mitigate CVE-2022-23937

Immediate Actions Required

• Identify all VxWorks 6.9 and 7.0 deployments in your environment with IKE functionality enabled
• Apply vendor patches from Wind River as soon as available for your specific platform
• Implement network segmentation to restrict access to IKE services on embedded devices
• Consider disabling IKE services on systems where VPN functionality is not required

Patch Information

Wind River has released security updates addressing this vulnerability. Administrators should consult the Wind River CVE List and Wind River Security Notices for specific patch versions and installation instructions. Due to the nature of embedded systems, firmware updates may require coordination with device manufacturers or system integrators.

Workarounds

• Disable IKE/IPsec services on affected devices where not operationally required
• Implement strict firewall rules to limit IKE traffic (UDP 500/4500) to trusted sources only
• Deploy network-level filtering to block malformed IKE packets before they reach vulnerable devices
• Use VPN concentrators or security gateways in front of embedded systems to terminate IKE connections

# Example firewall configuration to restrict IKE access
# Allow IKE only from trusted management network
iptables -A INPUT -p udp --dport 500 -s 10.0.0.0/8 -j ACCEPT
iptables -A INPUT -p udp --dport 4500 -s 10.0.0.0/8 -j ACCEPT
iptables -A INPUT -p udp --dport 500 -j DROP
iptables -A INPUT -p udp --dport 4500 -j DROP