CVE-2024-8829 in PDF-XChange
Summary
by MITRE • 11/23/2024
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 buffer. An attacker can leverage this in conjunction with other vulnerabilities to execute arbitrary code in the context of the current process. Was ZDI-CAN-24314.
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Analysis
by VulDB Data Team • 03/09/2025
The CVE-2024-8829 vulnerability represents a critical out-of-bounds read condition within the PDF-XChange Editor software that specifically affects the parsing of EMF (Enhanced Metafile) files. This vulnerability resides in the software's handling of user-supplied data during the EMF file processing workflow, creating a significant security risk for affected installations. The flaw manifests when the application attempts to parse EMF files without adequate validation of input parameters, leading to memory access violations that can result in information disclosure. The vulnerability's classification as an information disclosure issue stems from the fact that attackers can potentially read memory contents beyond the intended buffer boundaries, potentially exposing sensitive data such as stack contents, heap data, or other process memory structures. This type of vulnerability is particularly dangerous because it can serve as a stepping stone for more severe exploits, as the leaked information might contain pointers, credentials, or other sensitive data that could be leveraged in subsequent attacks.
The technical implementation of this vulnerability follows a classic buffer over-read pattern that aligns with CWE-125, which describes out-of-bounds read conditions in software systems. When PDF-XChange Editor processes an EMF file, it allocates memory buffers to store file data but fails to validate the size or structure of the incoming EMF data before reading from it. This allows an attacker to craft a malicious EMF file that, when processed by the vulnerable software, causes the application to read memory locations beyond the allocated buffer boundaries. The lack of proper bounds checking creates an exploitable condition where the application's memory management becomes compromised, potentially exposing internal application state or system information that should remain confidential. The vulnerability's exploitation requires user interaction, typically through visiting a malicious webpage or opening a specially crafted EMF file, which aligns with ATT&CK technique T1203 for legitimate user interaction required for exploitation.
The operational impact of CVE-2024-8829 extends beyond simple information disclosure, as the vulnerability can potentially enable more sophisticated attack vectors when combined with other exploits. Attackers can leverage the information disclosure to gather intelligence about the target system's memory layout, which is invaluable for developing more effective exploitation techniques. The vulnerability's remote exploitation capability means that attackers can potentially compromise systems without requiring physical access or local network presence, making it particularly dangerous in enterprise environments where users may inadvertently encounter malicious content. When combined with other vulnerabilities, this out-of-bounds read condition could potentially lead to arbitrary code execution, as the leaked memory information might contain return addresses, function pointers, or other elements necessary for successful exploitation. The fact that this vulnerability was tracked as ZDI-CAN-24314 indicates it was identified through coordinated vulnerability disclosure processes, highlighting the importance of proper vulnerability management and timely patch deployment.
Organizations affected by this vulnerability should implement immediate mitigations to protect their systems from potential exploitation. The primary recommendation involves applying the vendor-provided patches or updates that address the EMF file parsing logic and implement proper bounds checking mechanisms. Until patches are deployed, administrators should consider implementing network-level controls to block or filter EMF file content, particularly when it originates from untrusted sources. The vulnerability's requirement for user interaction means that security awareness training for end users becomes crucial, as users need to be educated about the risks of opening untrusted files or visiting suspicious websites. Additionally, system administrators should monitor for unusual network activity or file access patterns that might indicate exploitation attempts. The vulnerability's nature suggests that implementing application whitelisting policies for PDF-XChange Editor and related file processing components could provide an additional layer of protection, as this would limit the execution of potentially malicious files to only those that have been explicitly approved and validated by security policies.