CVE-2023-31275: Kingsoft WPS Office RCE Vulnerability

CVE-2023-31275 Overview

An uninitialized pointer use vulnerability exists in the functionality of WPS Office 11.2.0.11537 that handles Data elements in an Excel file. A specially crafted malformed file can lead to remote code execution. An attacker can provide a malicious file to trigger this vulnerability.

Critical Impact

This vulnerability allows remote code execution through malicious Excel files, potentially enabling attackers to gain complete control of affected systems when users open crafted documents.

Affected Products

• Kingsoft WPS Office 11.2.0.11537

Discovery Timeline

• 2023-11-27 - CVE CVE-2023-31275 published to NVD
• 2025-11-04 - Last updated in NVD database

Technical Details for CVE-2023-31275

Vulnerability Analysis

This vulnerability is classified as an uninitialized pointer use (CWE-457: Use of Uninitialized Variable, CWE-908: Use of Uninitialized Resource). The flaw exists within the WPS Office spreadsheet component responsible for parsing Data elements in Excel files. When processing specially crafted Excel documents, the application fails to properly initialize a pointer variable before use, leading to unpredictable behavior that an attacker can exploit for arbitrary code execution.

The local attack vector requires user interaction—specifically, the victim must open a malicious Excel file. However, once the file is opened, the exploitation requires no additional privileges and can result in complete compromise of confidentiality, integrity, and availability on the affected system.

Root Cause

The root cause stems from improper memory initialization within the Excel file parsing routines of WPS Office. When handling specific Data elements within a spreadsheet file, the application declares a pointer variable but fails to initialize it before dereferencing. This uninitialized pointer contains garbage values from the stack or heap memory, which an attacker can potentially influence through careful crafting of the malicious document to achieve code execution.

Attack Vector

The attack requires an attacker to craft a malicious Excel file containing specially formed Data elements designed to exploit the uninitialized pointer condition. The attack vector is local, meaning the attacker must deliver the malicious file to the victim through social engineering methods such as:

• Phishing emails with malicious Excel attachments
• Hosting malicious files on compromised or attacker-controlled websites
• Distribution through file-sharing platforms or messaging applications

When the victim opens the crafted Excel file using the vulnerable version of WPS Office, the uninitialized pointer is dereferenced during file parsing. By controlling the memory state at the time of dereference, an attacker can redirect execution flow to achieve arbitrary code execution with the privileges of the current user.

For detailed technical analysis of this vulnerability, refer to the Talos Intelligence Vulnerability Report.

Detection Methods for CVE-2023-31275

Indicators of Compromise

• Unusual WPS Office process behavior including unexpected child processes or network connections
• Excel files with malformed or anomalous Data element structures
• Crash dumps or error reports from WPS Office indicating memory access violations
• Suspicious file access patterns following the opening of spreadsheet documents

Detection Strategies

• Deploy endpoint detection solutions capable of monitoring for exploitation attempts targeting office productivity applications
• Implement file scanning for malformed Excel documents before they reach end users
• Monitor for WPS Office crashes or abnormal terminations that may indicate exploitation attempts
• Use behavioral analysis to detect post-exploitation activities following document opening

Monitoring Recommendations

• Enable detailed logging for WPS Office application events and crashes
• Configure security tools to alert on suspicious process creation chains originating from WPS Office
• Monitor network traffic from WPS Office processes for unexpected connections
• Implement file integrity monitoring on sensitive systems to detect unauthorized changes

How to Mitigate CVE-2023-31275

Immediate Actions Required

• Update WPS Office to a version newer than 11.2.0.11537 that contains a fix for this vulnerability
• Educate users about the risks of opening Excel files from untrusted or unknown sources
• Implement email filtering to scan and quarantine suspicious spreadsheet attachments
• Consider temporarily restricting the ability to open external Excel files until patching is complete

Patch Information

Organizations should check with Kingsoft for the latest security updates addressing this vulnerability. Upgrade WPS Office to the most recent available version to ensure protection against this and other known vulnerabilities. Refer to the Talos Intelligence Vulnerability Report for additional technical details.

Workarounds

• Block or quarantine Excel files from untrusted sources at the email gateway
• Use alternative spreadsheet applications for opening files from unknown sources until patching
• Implement application control policies to restrict WPS Office execution in high-security environments
• Enable exploit protection features in endpoint security solutions to help mitigate memory corruption attacks