CVE-2024-8835 in PDF-XChange
Summary
by MITRE • 11/23/2024
PDF-XChange Editor JB2 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 JB2 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-24320.
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Analysis
by VulDB Data Team • 03/09/2025
The CVE-2024-8835 vulnerability represents a critical out-of-bounds read flaw in PDF-XChange Editor's handling of JB2 image files, classified under CWE-125 as improper validation of array index boundaries. This vulnerability exists within the JB2 file parsing component of the PDF-XChange Editor software, which is widely used for PDF document creation, editing, and viewing. The flaw manifests when the application processes maliciously crafted JB2 files that contain malformed data structures, specifically in how the software handles array indexing during image decompression operations. The vulnerability enables attackers to manipulate memory access patterns that extend beyond allocated buffer boundaries, creating opportunities for information disclosure and potential code execution.
The technical implementation of this vulnerability stems from insufficient input validation mechanisms within the JB2 parsing engine. When PDF-XChange Editor encounters a JB2 file, it attempts to parse the image data structure without adequate boundary checks on array indices used for decompressing the image components. This allows an attacker to craft a specially formatted JB2 file that triggers memory access violations, resulting in the disclosure of sensitive data from adjacent memory locations. The vulnerability operates at the memory management level, where the application fails to validate the length and structure of incoming data before attempting to read from memory regions. This type of flaw aligns with ATT&CK technique T1059.007 for command and scripting interpreter execution, as the vulnerability can be leveraged to gain unauthorized access to system information that could aid in further exploitation.
The operational impact of this vulnerability extends beyond simple information disclosure, as it creates a potential pathway for more sophisticated attacks within the context of the PDF-XChange Editor application. An attacker who successfully exploits this vulnerability could access memory contents that may contain sensitive information such as encryption keys, user credentials, or application-specific data structures. The requirement for user interaction through visiting a malicious webpage or opening a malicious file aligns with ATT&CK tactic TA0001 for initial access, making this vulnerability particularly dangerous in phishing campaigns or compromised websites. The vulnerability's classification as a remote code execution vector through combination with other exploits demonstrates the severity of the underlying memory corruption issue, as described in the ZDI-CAN-24320 reference. This weakness can be exploited in targeted attacks against users who regularly process documents containing embedded JB2 images.
Mitigation strategies for CVE-2024-8835 should prioritize immediate software updates from the vendor, as the vulnerability affects core functionality within the PDF-XChange Editor application. Organizations should implement network-based protections such as web application firewalls that can detect and block malicious JB2 file content, particularly when these files are embedded within web pages or email attachments. System administrators should consider implementing strict file type validation and sandboxing mechanisms for document processing, ensuring that JB2 files are not automatically processed without proper validation. The vulnerability's nature suggests that implementing input sanitization at the application level, including proper array boundary checking and memory access validation, would effectively prevent exploitation. Additionally, user education regarding the dangers of opening untrusted files and visiting suspicious websites remains crucial, as the attack vector relies heavily on social engineering aspects to achieve successful exploitation of this memory corruption vulnerability.