CVE-2023-42110 in PDF-XChange Editor
Summary
by MITRE • 05/03/2024
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-22137.
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Analysis
by VulDB Data Team • 05/03/2024
This vulnerability resides within PDF-XChange Editor's handling of EMF (Enhanced Metafile) files, representing a critical information disclosure flaw that enables remote attackers to extract sensitive data from affected systems. The vulnerability stems from insufficient input validation during the parsing process, specifically when processing user-supplied EMF file content. When the application encounters an improperly formatted EMF file, it fails to properly bounds-check memory accesses, leading to out-of-bounds read operations that can expose confidential information stored in adjacent memory locations.
The technical implementation of this vulnerability falls under CWE-125, which describes out-of-bounds read conditions where a program reads data past the end of a valid buffer. This particular flaw operates at the file parsing layer within PDF-XChange Editor's EMF processing subsystem, where the application attempts to interpret and render metafile graphics without adequate safeguards against malformed input structures. The lack of proper validation allows attackers to craft malicious EMF files that trigger memory access violations, potentially revealing system memory contents including encryption keys, authentication tokens, or other sensitive data.
From an operational perspective, this vulnerability requires user interaction to be exploited successfully, making it a client-side attack vector that typically manifests through social engineering campaigns. An attacker would need to entice a victim to visit a malicious webpage hosting the crafted EMF file or to open a specially prepared document containing the vulnerable file format. The impact extends beyond simple information disclosure as this vulnerability can serve as a stepping stone for more sophisticated attacks, potentially enabling adversaries to gather intelligence about system configurations, software versions, and memory layouts that could facilitate subsequent exploitation attempts.
The security implications of this vulnerability align with ATT&CK technique T1059.007, which covers scripting languages and command execution through file processing utilities. Attackers can leverage the information disclosure aspect to better understand target environments before attempting more destructive operations. The ZDI-CAN-22137 identifier indicates this was recognized by the Zero Day Initiative vulnerability research program, highlighting its significance in the cybersecurity community. Organizations utilizing PDF-XChange Editor should prioritize patching this vulnerability as it represents a potential gateway for privilege escalation attacks and could be combined with other vulnerabilities to achieve arbitrary code execution within the application's security context.
Mitigation strategies should include immediate deployment of vendor-provided patches or updates addressing the EMF parsing logic, implementation of network-based intrusion detection rules targeting suspicious EMF file patterns, and user education regarding dangerous file attachments. Additionally, organizations should consider implementing application whitelisting policies to restrict execution of potentially malicious file formats and establish monitoring procedures for unusual memory access patterns that could indicate exploitation attempts. The vulnerability demonstrates the critical importance of proper input validation in file processing applications, particularly those handling rich media formats like EMF files that require complex parsing logic and extensive memory management.