CVE-2025-0902: PDF-XChange Editor Info Disclosure Flaw

CVE-2025-0902 Overview

CVE-2025-0902 is an out-of-bounds read vulnerability affecting PDF-XChange Editor's XPS file parsing functionality. This vulnerability allows remote attackers to disclose sensitive information on affected installations of PDF-XChange Editor. User interaction is required to exploit this vulnerability, as the target must visit a malicious page or open a malicious file.

The specific flaw exists within the parsing of XPS files. The issue results from the lack of proper validation of user-supplied data, which can result in a read past the end of an allocated object. An attacker can leverage this vulnerability in conjunction with other vulnerabilities to execute arbitrary code in the context of the current process.

Critical Impact

This out-of-bounds read vulnerability enables information disclosure and can be chained with other exploits to achieve arbitrary code execution in the context of the current process.

Affected Products

• PDF-XChange Editor (all versions prior to patch)
• PDF-XChange PDF-XChange Editor

Discovery Timeline

• 2025-02-11 - CVE-2025-0902 published to NVD
• 2025-02-12 - Last updated in NVD database

Technical Details for CVE-2025-0902

Vulnerability Analysis

This vulnerability is classified under CWE-125 (Out-of-bounds Read), a common memory safety issue where an application reads data beyond the boundaries of an allocated memory buffer. In the context of PDF-XChange Editor, the flaw manifests during the parsing of XPS (XML Paper Specification) files.

When processing malformed or specially crafted XPS files, the parser fails to properly validate user-supplied data before using it to determine read boundaries. This allows an attacker to craft a malicious XPS file that triggers a read operation past the end of an allocated object, potentially exposing sensitive memory contents.

The network attack vector indicates that exploitation can occur remotely, though user interaction is required—the victim must open a malicious file or visit a malicious webpage hosting the exploit. When successfully exploited, this vulnerability can be combined with additional exploits to achieve arbitrary code execution within the context of the current process.

Root Cause

The root cause of this vulnerability lies in insufficient bounds checking within the XPS file parsing routines of PDF-XChange Editor. When processing XPS file structures, the application does not properly validate the size and offset parameters derived from user-supplied data. This allows an attacker to manipulate these values to force the parser to read memory beyond the intended buffer boundaries.

The lack of proper input validation before memory access operations is a fundamental memory safety issue that can lead to information disclosure and, when chained with other vulnerabilities, arbitrary code execution.

Attack Vector

The attack vector for CVE-2025-0902 requires user interaction through one of two primary methods:

1. Malicious File Delivery: An attacker crafts a specially formatted XPS file containing malformed data structures designed to trigger the out-of-bounds read. The victim must open this file using PDF-XChange Editor.

2. Malicious Webpage: An attacker hosts a malicious XPS file on a webpage, leveraging browser integrations or file handling to trigger the vulnerability when the victim visits the page.

The vulnerability exploitation process involves crafting an XPS file with manipulated size or offset values that cause the parser to read beyond allocated buffer boundaries. For detailed technical information, refer to the Zero Day Initiative Advisory ZDI-25-072.

Detection Methods for CVE-2025-0902

Indicators of Compromise

• Unexpected crashes or errors when opening XPS files in PDF-XChange Editor
• Memory access violations or exception logs related to XPS parsing operations
• Suspicious XPS file attachments received via email or downloaded from untrusted sources
• Application instability following the processing of XPS documents

Detection Strategies

• Monitor PDF-XChange Editor processes for unusual memory access patterns or crash signatures
• Implement endpoint detection rules for abnormal XPS file handling behavior
• Deploy email gateway scanning to identify and quarantine suspicious XPS file attachments
• Use application whitelisting to restrict execution of PDF-XChange Editor to trusted file sources

Monitoring Recommendations

• Enable detailed logging for PDF-XChange Editor operations
• Configure SIEM alerts for application crash events associated with XPS file processing
• Monitor for unusual network traffic patterns associated with XPS file downloads
• Implement file integrity monitoring for XPS files in sensitive directories

How to Mitigate CVE-2025-0902

Immediate Actions Required

• Update PDF-XChange Editor to the latest patched version when available
• Restrict opening of XPS files from untrusted or unknown sources
• Implement user awareness training regarding the risks of opening files from untrusted sources
• Consider temporarily disabling XPS file handling if not critical to business operations

Patch Information

Users should monitor PDF-XChange vendor communications for security updates addressing this vulnerability. The advisory was published by the Zero Day Initiative under ZDI-25-072. Organizations should apply vendor patches as soon as they become available and verify the update resolves the out-of-bounds read condition in XPS file parsing.

Workarounds

• Block or quarantine XPS files at the email gateway level until patches are applied
• Use alternative document viewers that are not affected by this vulnerability for XPS files
• Implement strict file source validation policies, restricting XPS file access to trusted network locations only
• Configure endpoint protection to monitor and alert on suspicious XPS file processing behavior

Organizations should prioritize applying vendor patches once available, as workarounds provide limited protection and may impact business operations that rely on XPS file processing capabilities.