CVE-2024-2971 in Xpdf
Summary
by MITRE • 03/27/2024
Out-of-bounds array write in Xpdf 4.05 and earlier, triggered by negative object number in indirect reference in the input PDF file.
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Analysis
by VulDB Data Team • 09/08/2025
The vulnerability identified as CVE-2024-2971 represents a critical out-of-bounds array write flaw within the Xpdf library version 4.05 and earlier. This security defect manifests when processing PDF files containing malformed indirect references with negative object numbers, creating a scenario where the application attempts to write data beyond the allocated memory boundaries of an array structure. The Xpdf library, widely used for PDF rendering and processing across various platforms and applications, becomes susceptible to this vulnerability when encountering specially crafted PDF documents that exploit the improper handling of object number validation.
The technical root cause of this vulnerability stems from inadequate input validation within the PDF parsing engine of Xpdf. When the library encounters an indirect reference in a PDF file where the object number is negative, it fails to properly validate this value before using it as an array index. This failure directly violates the principles of secure coding practices and represents a classic example of buffer overflow vulnerability classified under CWE-787. The negative object number, when used as an array subscript, results in unpredictable memory access patterns that can lead to memory corruption, application crashes, or potentially more severe consequences depending on the execution environment.
The operational impact of CVE-2024-2971 extends significantly across various threat scenarios and attack vectors. An attacker could exploit this vulnerability by crafting malicious PDF files containing negative object numbers in indirect references, which when processed by applications utilizing the vulnerable Xpdf library, could trigger arbitrary code execution. This vulnerability particularly affects systems where PDF processing is prevalent, including web browsers, document viewers, email clients, and document management systems that rely on Xpdf for PDF rendering. The potential for remote code execution makes this vulnerability particularly dangerous in environments where users might encounter untrusted PDF content, creating a significant risk for enterprise networks and individual users alike.
Mitigation strategies for CVE-2024-2971 should prioritize immediate remediation through software updates to Xpdf version 4.06 or later, which contains the necessary patches to address the out-of-bounds array write issue. Organizations should also implement defensive measures such as validating PDF files through sandboxed environments, employing content filtering solutions, and restricting PDF processing capabilities in high-risk scenarios. Additionally, network administrators should consider implementing web application firewalls and intrusion detection systems that can identify and block potentially malicious PDF content. The vulnerability's classification under ATT&CK technique T1203 (Exploitation for Client Execution) highlights the importance of maintaining up-to-date security controls and monitoring for suspicious PDF-related activities. System administrators should also conduct comprehensive vulnerability assessments to identify all systems that may be utilizing vulnerable versions of Xpdf, ensuring that the patching process is thorough and complete across all affected platforms and applications.