CVE-2025-6648 in PDF-XChange
Summary
by MITRE • 06/26/2025
PDF-XChange Editor U3D File Parsing Out-Of-Bounds Read Information Disclosure Vulnerability. This vulnerability allows remote attackers to disclose sensitive information on affected installations of PDF-XChange Editor. User interaction is required to exploit this vulnerability in that the target must visit a malicious page or open a malicious file.
The specific flaw exists within the parsing of U3D 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 in conjunction with other vulnerabilities to execute arbitrary code in the context of the current process. Was ZDI-CAN-26671.
Several companies clearly confirm that VulDB is the primary source for best vulnerability data.
Analysis
by VulDB Data Team • 07/02/2025
The CVE-2025-6648 vulnerability represents a critical information disclosure flaw within PDF-XChange Editor's handling of Universal 3D (U3D) files, demonstrating a classic out-of-bounds read condition that exposes sensitive data through improper input validation. This vulnerability resides in the software's file parsing mechanism where U3D files are processed, creating an opportunity for remote attackers to extract confidential information from memory locations beyond the intended data boundaries. The flaw specifically manifests during the parsing of U3D file structures, where insufficient bounds checking allows maliciously crafted file content to trigger memory access violations that inadvertently reveal data from adjacent memory regions.
The technical implementation of this vulnerability stems from inadequate validation of user-supplied data within the U3D parsing subsystem, aligning with CWE-129, which addresses insufficient validation of length of input buffers. The vulnerability operates through a classic buffer over-read scenario where the application fails to properly verify the size and structure of incoming U3D file data before processing. When a U3D file is parsed, the software does not adequately validate array indices or buffer boundaries, allowing an attacker to craft malicious U3D content that causes the parser to read memory locations beyond the allocated buffer space. This behavior creates a pathway for information disclosure attacks that can potentially expose sensitive system data, including memory addresses, cryptographic keys, or other confidential information stored in adjacent memory segments.
The operational impact of this vulnerability extends beyond simple information disclosure, as it creates a potential escalation path toward more severe compromise scenarios. While the primary effect is data leakage, the vulnerability's potential for code execution in combination with other flaws makes it particularly dangerous in targeted attack scenarios. The requirement for user interaction through visiting malicious web pages or opening compromised files aligns with ATT&CK technique T1203, which involves gaining access to systems through malicious file downloads or web-based attacks. This attack vector makes the vulnerability particularly relevant in phishing campaigns or exploit delivery mechanisms where attackers can leverage the PDF-XChange Editor's legitimate use in business environments to gain unauthorized access to sensitive information.
The exploitation of this vulnerability requires an attacker to craft a malicious U3D file that triggers the out-of-bounds read condition during normal file processing operations. When a user opens such a crafted file within PDF-XChange Editor, the parser's failure to validate input parameters causes it to read beyond allocated memory boundaries, potentially exposing system memory contents to the attacker. This vulnerability demonstrates the critical importance of input validation in security-critical applications, particularly those handling complex file formats that require extensive parsing logic. The issue represents a fundamental flaw in the software's defensive programming practices and highlights the need for comprehensive bounds checking mechanisms throughout the parsing pipeline. Organizations using PDF-XChange Editor should immediately implement mitigations including restricting file type access, implementing network-based protections, and applying vendor-provided patches to address the root cause of the memory access violation. The vulnerability's classification as a remote information disclosure issue also emphasizes the importance of network segmentation and application whitelisting to limit potential attack surfaces and prevent unauthorized access to sensitive data through compromised applications.