CVE-2026-3422: U-Office Force RCE Vulnerability

CVE-2026-3422 Overview

U-Office Force, developed by e-Excellence, contains an Insecure Deserialization vulnerability (CWE-502) that allows unauthenticated remote attackers to execute arbitrary code on the server. By sending maliciously crafted serialized content to the application, attackers can achieve full system compromise without requiring any prior authentication or user interaction.

Critical Impact

This vulnerability enables unauthenticated remote code execution, potentially allowing attackers to gain complete control over affected U-Office Force servers.

Affected Products

• U-Office Force (specific versions not disclosed in advisory)

Discovery Timeline

• 2026-03-02 - CVE-2026-3422 published to NVD
• 2026-03-02 - Last updated in NVD database

Technical Details for CVE-2026-3422

Vulnerability Analysis

This Insecure Deserialization vulnerability in U-Office Force represents a severe security flaw that exposes organizations to remote code execution attacks. The vulnerability occurs when the application accepts and processes serialized data from untrusted sources without proper validation or sanitization.

Insecure deserialization vulnerabilities arise when applications deserialize data from external sources without verifying the integrity or safety of that data. In the case of U-Office Force, attackers can craft malicious serialized payloads that, when processed by the server, execute arbitrary code in the context of the application. This type of vulnerability is particularly dangerous because it requires no authentication, meaning any attacker with network access to the vulnerable application can potentially exploit it.

The network-accessible nature of this vulnerability, combined with the lack of authentication requirements, makes it an attractive target for threat actors seeking initial access to corporate networks.

Root Cause

The root cause of CVE-2026-3422 is the application's failure to properly validate and sanitize serialized content before deserialization. When an application blindly trusts and processes serialized objects from untrusted sources, it opens the door for object injection attacks. The deserialization process can trigger code execution through various mechanisms, including:

• Gadget chains within the application's classpath
• Magic methods that execute automatically during object reconstruction
• Callbacks or hooks that are invoked during the deserialization process

Attack Vector

The attack vector for this vulnerability is network-based, requiring no authentication or user interaction. An attacker can exploit this vulnerability by:

1. Identifying an endpoint in U-Office Force that accepts serialized data
2. Crafting a malicious serialized payload containing code execution gadgets
3. Sending the payload to the vulnerable endpoint
4. Achieving arbitrary code execution when the server deserializes the malicious content

The exploitation does not require any special privileges or complex attack conditions, making it highly accessible to attackers with varying skill levels once a suitable exploit is developed.

For technical details on this vulnerability, refer to the TW-CERT Security Advisory.

Detection Methods for CVE-2026-3422

Indicators of Compromise

• Unusual process spawning from the U-Office Force application process
• Unexpected network connections originating from the server hosting U-Office Force
• Presence of unfamiliar files or scripts in application directories
• Anomalous serialized data patterns in application logs or network traffic

Detection Strategies

• Monitor HTTP/HTTPS traffic to U-Office Force for suspicious serialized payloads with unusual class references or gadget chain indicators
• Implement application-level logging to capture deserialization events and flag unexpected object types
• Deploy network intrusion detection signatures targeting common deserialization exploit patterns
• Configure endpoint detection to alert on child processes spawned by the U-Office Force application

Monitoring Recommendations

• Enable verbose logging on U-Office Force servers to capture incoming requests and deserialization activities
• Implement network segmentation monitoring to detect lateral movement following potential exploitation
• Set up alerts for any outbound connections from U-Office Force servers to unexpected destinations
• Monitor for privilege escalation attempts or credential dumping activities on affected systems

How to Mitigate CVE-2026-3422

Immediate Actions Required

• Consult vendor advisories from e-Excellence for available security patches
• Restrict network access to U-Office Force servers to trusted IP ranges only
• Implement Web Application Firewall (WAF) rules to filter suspicious serialized content
• Monitor affected systems for signs of compromise while awaiting a vendor patch

Patch Information

Organizations should consult the official security advisories from TW-CERT for the latest patch information and remediation guidance. Review the TW-CERT Security Advisory (English) and TW-CERT Security Alert (Chinese) for vendor-specific guidance on available updates.

Workarounds

• Implement strict network access controls limiting connectivity to U-Office Force to only authorized users and systems
• Deploy a reverse proxy or WAF in front of U-Office Force to inspect and filter incoming requests for malicious serialized content
• Consider temporarily disabling external access to U-Office Force until a patch is available
• Enable application sandboxing or containerization to limit the impact of successful exploitation

# Example network restriction using iptables (adapt to your environment)
# Restrict access to U-Office Force port to trusted network only
iptables -A INPUT -p tcp --dport 443 -s 10.0.0.0/8 -j ACCEPT
iptables -A INPUT -p tcp --dport 443 -j DROP