CVE-2024-3247 in Xpdf
Summary
by MITRE • 04/03/2024
In Xpdf 4.05 (and earlier), a PDF object loop in an object stream leads to infinite recursion and a stack overflow.
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Analysis
by VulDB Data Team • 12/05/2025
The vulnerability identified as CVE-2024-3247 affects Xpdf version 4.05 and earlier, representing a critical stack overflow condition that arises from improper handling of PDF object streams. This flaw exists within the PDF parsing engine of Xpdf, which is widely used for rendering and processing PDF documents across various platforms and applications. The issue manifests when the software encounters a malformed PDF object stream containing recursive references that create an infinite loop during object parsing operations.
The technical root cause of this vulnerability stems from insufficient boundary checking and recursion depth limitations within the PDF object stream processing logic. When Xpdf encounters a PDF object stream where objects reference each other in a circular pattern, the parser enters an infinite recursion loop that consumes stack memory without proper termination conditions. This behavior directly corresponds to CWE-674, which describes insufficient control of recursion depth, and aligns with CWE-121, representing stack-based buffer overflow conditions. The vulnerability allows an attacker to craft malicious PDF files that trigger this recursive parsing behavior, leading to application crashes or potential memory corruption scenarios.
From an operational perspective, this vulnerability presents significant risks to organizations relying on Xpdf for PDF processing, particularly in environments where untrusted PDF documents are handled. The infinite recursion can cause denial of service conditions, application instability, and potential system crashes when legitimate users or automated systems process maliciously crafted PDF files. This vulnerability is particularly concerning in web applications, email systems, and document processing pipelines where PDF files are automatically rendered or analyzed without proper sanitization. The attack surface extends beyond simple exploitation to include scenarios where PDF processing occurs in server environments, potentially leading to resource exhaustion attacks that can impact system availability.
The impact of CVE-2024-3247 aligns with several ATT&CK techniques including T1203, which covers exploitation for privilege escalation through software vulnerabilities, and T1499, covering network denial of service attacks. Organizations using Xpdf in production environments must implement immediate mitigations including updating to version 4.06 or later where this vulnerability has been patched, implementing PDF validation and sanitization layers, and establishing proper input validation for PDF files. Additionally, deployment of intrusion detection systems that can identify malformed PDF processing patterns and implementing application sandboxing for PDF rendering operations can help reduce the risk exposure. The vulnerability also highlights the importance of robust input validation in document processing libraries and demonstrates the critical need for proper recursion depth controls in parsing engines that handle complex structured data formats like PDFs.