CVE-2022-42403 in PDF-XChange Editor
Summary
by MITRE • 01/26/2023
This vulnerability allows remote attackers to execute arbitrary code 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 PDF files. The issue results from the lack of proper validation of the length of user-supplied data prior to copying it to a fixed-length heap-based buffer. An attacker can leverage this vulnerability to execute code in the context of the current process. Was ZDI-CAN-18892.
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Analysis
by VulDB Data Team • 04/29/2025
CVE-2022-42403 represents a critical buffer overflow vulnerability affecting PDF-XChange Editor, a widely used PDF viewing and editing application. This vulnerability falls under the Common Weakness Enumeration category CWE-121, which encompasses classic stack-based and heap-based buffer overflow conditions. The flaw manifests during the parsing of PDF files when the application fails to properly validate the length of user-supplied data before copying it into a fixed-length heap-based buffer. This inadequate input validation creates an exploitable condition where maliciously crafted PDF content can trigger unauthorized code execution.
The attack vector requires user interaction, making it particularly dangerous as victims must visit a malicious webpage or open a specially crafted PDF file to be compromised. This delivery mechanism aligns with common social engineering tactics used in targeted attacks and phishing campaigns. The vulnerability exists in the PDF parsing engine of PDF-XChange Editor, specifically within how the application handles certain data structures during document processing. When an attacker constructs a malicious PDF file with oversized data fields, the application's insufficient bounds checking allows the data to overflow into adjacent memory regions, potentially overwriting critical program structures or executable code.
The operational impact of this vulnerability extends beyond simple code execution, as it allows attackers to operate within the security context of the currently running PDF-XChange Editor process. This privilege escalation capability means that successful exploitation could lead to full system compromise, especially if the application runs with elevated privileges. The heap-based nature of the buffer overflow provides attackers with additional flexibility in crafting exploits, as heap corruption can be more subtle and harder to detect than stack-based overflows. Attackers can leverage this vulnerability to install malware, steal sensitive data, or establish persistent access to affected systems.
Mitigation strategies should focus on immediate patch application from the vendor, as this vulnerability has been addressed in subsequent releases of PDF-XChange Editor. Organizations should implement network-based protections such as web application firewalls and content filtering solutions to block access to known malicious PDF content. Additionally, user education programs should emphasize the importance of avoiding untrusted PDF files and suspicious web pages. System administrators should consider implementing application whitelisting policies to restrict execution of unauthorized PDF processing applications. The vulnerability demonstrates the importance of proper input validation and bounds checking in software development, particularly for applications handling untrusted data formats like PDF documents. Organizations should also conduct regular vulnerability assessments targeting PDF processing applications and maintain up-to-date threat intelligence to identify potential exploitation attempts.