CVE-2023-1967: Keysight N8844A Deserialization Vulnerability

CVE-2023-1967 Overview

CVE-2023-1967 is a critical insecure deserialization vulnerability affecting the Keysight N8844A Data Analytics Web Service. The application deserializes untrusted data without sufficiently verifying that the resulting data will be valid, potentially allowing remote attackers to execute arbitrary code or compromise system integrity.

Critical Impact

This vulnerability allows unauthenticated remote attackers to exploit insecure deserialization in the N8844A Data Analytics Web Service, potentially leading to complete system compromise including unauthorized code execution, data theft, and service disruption.

Affected Products

• Keysight N8844A Data Analytics Web Service (all versions)

Discovery Timeline

• April 27, 2023 - CVE-2023-1967 published to NVD
• January 16, 2025 - Last updated in NVD database

Technical Details for CVE-2023-1967

Vulnerability Analysis

This vulnerability falls under CWE-502 (Deserialization of Untrusted Data), a well-known class of security weaknesses that occurs when applications accept serialized objects from untrusted sources without proper validation. The Keysight N8844A Data Analytics Web Service fails to implement adequate verification of deserialized data, creating a pathway for attackers to inject malicious payloads.

The network-accessible nature of this web service significantly increases the attack surface, as exploitation does not require authentication, user interaction, or special privileges. An attacker with network access to the vulnerable service can craft malicious serialized objects that, when processed by the application, execute arbitrary commands or manipulate application behavior.

Root Cause

The root cause of this vulnerability is insufficient validation of serialized data before deserialization occurs in the N8844A Data Analytics Web Service. When an application deserializes data, it reconstructs objects from a serialized format (such as JSON, XML, or binary streams). Without proper validation, attackers can craft malicious serialized payloads containing embedded commands or object chains that execute during the deserialization process.

The vulnerability exists because the web service trusts incoming serialized data implicitly, failing to implement integrity checks, type restrictions, or input sanitization that would prevent the reconstruction of dangerous object types.

Attack Vector

The attack vector for CVE-2023-1967 is network-based, meaning attackers can exploit this vulnerability remotely without requiring physical access to the target system. The exploitation process typically involves:

1. An attacker identifies an endpoint in the N8844A Data Analytics Web Service that accepts serialized data
2. The attacker crafts a malicious serialized payload containing gadget chains or embedded commands
3. The payload is sent to the vulnerable service over the network
4. The service deserializes the malicious data without validation, triggering code execution or other malicious behavior

Insecure deserialization vulnerabilities can lead to severe consequences including remote code execution, authentication bypass, privilege escalation, or denial of service. For detailed technical information about this vulnerability, refer to the CISA ICS Advisory ICSA-23-115-01.

Detection Methods for CVE-2023-1967

Indicators of Compromise

• Unusual network traffic patterns targeting the N8844A Data Analytics Web Service endpoints
• Unexpected serialized data payloads in web service requests, particularly those containing unusual class references or gadget chain signatures
• Anomalous process spawning or command execution originating from the web service process
• Unexpected file system modifications or network connections initiated by the N8844A service

Detection Strategies

• Deploy network intrusion detection systems (NIDS) with signatures for common deserialization attack patterns
• Monitor application logs for deserialization errors or exceptions that may indicate exploitation attempts
• Implement web application firewalls (WAF) configured to inspect and filter potentially malicious serialized payloads
• Use endpoint detection and response (EDR) solutions to monitor for suspicious behavior from the N8844A service process

Monitoring Recommendations

• Enable verbose logging on the N8844A Data Analytics Web Service to capture detailed request information
• Monitor network traffic for anomalous POST requests containing serialized object streams
• Implement file integrity monitoring on the host system running the vulnerable service
• Configure SIEM alerts for any unusual activity associated with the N8844A service

How to Mitigate CVE-2023-1967

Immediate Actions Required

• Review and apply any available security updates or patches from Keysight for the N8844A Data Analytics Web Service
• Restrict network access to the vulnerable service using firewall rules, allowing only trusted IP addresses
• Implement network segmentation to isolate the N8844A service from critical infrastructure
• Consider temporarily disabling the service if it is not essential for operations until a patch is available

Patch Information

Organizations should consult the CISA ICS Advisory ICSA-23-115-01 for the latest vendor guidance and patch availability. Contact Keysight support directly for specific patch information and update schedules for the N8844A Data Analytics Web Service.

Workarounds

• Implement strict network access controls to limit which systems can communicate with the N8844A service
• Deploy a web application firewall (WAF) in front of the service to filter potentially malicious requests
• Enable input validation at the network perimeter to reject suspicious serialized data patterns
• Consider deploying the service in an isolated network segment with no direct internet exposure

# Example firewall rule to restrict access to N8844A service (adjust port as needed)
# Allow only specific trusted networks to access the service
iptables -A INPUT -p tcp --dport 443 -s 192.168.1.0/24 -j ACCEPT
iptables -A INPUT -p tcp --dport 443 -j DROP