CVE-2024-27331 in PDF-XChange Editor
Summary
by MITRE • 04/02/2024
PDF-XChange Editor EMF 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 EMF 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-22287.
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Analysis
by VulDB Data Team • 07/08/2025
The vulnerability identified as CVE-2024-27331 represents a critical information disclosure flaw within PDF-XChange Editor's handling of EMF (Enhanced Metafile) files, classified under CWE-125 as Out-of-Bounds Read. This vulnerability specifically affects the software's EMF file parsing functionality, where insufficient input validation allows maliciously crafted EMF files to trigger memory access violations that expose sensitive data from adjacent memory regions. The flaw operates at the boundary between legitimate file parsing and malicious data exploitation, creating a pathway for attackers to extract confidential information from the application's memory space.
The technical implementation of this vulnerability stems from improper bounds checking during EMF file processing within PDF-XChange Editor's rendering engine. When the application encounters an EMF file, it attempts to parse and render the vector graphics data without adequate validation of the file structure's integrity. This allows attackers to craft EMF files containing malformed data sequences that cause the parser to read memory locations beyond the intended buffer boundaries, potentially exposing system memory contents including stack data, heap information, or other sensitive application state. The vulnerability requires user interaction to exploit, meaning victims must either visit a malicious webpage or open a specially crafted EMF file, making it a client-side attack vector that aligns with ATT&CK technique T1203 for Exploitation for Client Execution.
The operational impact of this vulnerability extends beyond simple information disclosure, as it creates a potential stepping stone for more sophisticated attacks within the ATT&CK framework's privilege escalation and persistence phases. While the immediate effect involves reading sensitive memory contents, the vulnerability's potential for exploitation increases significantly when combined with other weaknesses, as noted in the original ZDI-CAN-22287 report. Attackers can leverage this out-of-bounds read to gather information about memory layout, application state, or even cryptographic keys that may be stored in adjacent memory regions. The vulnerability's presence in a widely used document editing application means that successful exploitation could provide attackers with sufficient information to conduct more targeted attacks against the victim's system or network.
Organizations should implement immediate mitigations including restricting access to EMF file types within PDF-XChange Editor, updating to patched versions when available, and implementing network-based protections such as web application firewalls that can detect and block malicious EMF file content. The vulnerability demonstrates the importance of proper input validation and bounds checking, particularly in applications that process untrusted file formats, and serves as a reminder of the critical need for defensive programming practices. Security teams should monitor for exploitation attempts through network traffic analysis and endpoint detection systems, paying particular attention to unusual file processing patterns or memory access violations that may indicate exploitation of this vulnerability.