CVE-2023-24808 : Security Advisory and Response

A denial of service vulnerability has been identified in a C library called PDFio, specifically in versions prior to 1.1.0. This vulnerability can be exploited by opening a corrupt PDF file using the pdfio parser, leading to a program crash that runs at 100% utilization and does not terminate.

Understanding CVE-2023-24808

The CVE-2023-24808 vulnerability pertains to a denial of service risk associated with the pdfio library when attempting to parse a maliciously crafted PDF file.

What is CVE-2023-24808?

PDFio is a C library designed for the reading and writing of PDF files. The vulnerability in versions before 1.1.0 allows attackers to create a PDF file that triggers an infinite loop in the pdfio parser, causing the affected program to consume resources excessively and fail to complete processing the file.

The Impact of CVE-2023-24808

The impact of CVE-2023-24808 is rated as MEDIUM with a CVSS base score of 5.3. While the availability impact is low, the vulnerability does not compromise confidentiality or integrity. Attack complexity is classified as low, with no user interaction required and no privileges needed.

Technical Details of CVE-2023-24808

The following technical details outline the vulnerability, affected systems, and exploitation mechanism.

Vulnerability Description

Crafted PDF files can trigger an infinite loop in the pdfio parser, leading to a denial of service condition. The vulnerable library runs at maximum capacity, unable to complete the processing of the malicious file.

Affected Systems and Versions

The affected vendor is Michael Sweet, and the vulnerable product is pdfio. Versions earlier than 1.1.0 are impacted by this vulnerability, requiring immediate attention for users relying on this library.

Exploitation Mechanism

An attacker uploads a specially crafted PDF file to a system that uses the pdfio library for parsing. The malicious PDF triggers an infinite loop within the parser, causing resource exhaustion and an unresponsive program.

Mitigation and Prevention

To address CVE-2023-24808, users are recommended to take immediate steps, adopt long-term security practices, and apply necessary patches and updates.

Immediate Steps to Take

Users should upgrade the pdfio library to version 1.1.0 or newer to mitigate the risk of DOS attacks through malicious PDF files.
Organizations relying on pdfio for processing PDF submissions should update their systems promptly to prevent exploitation of this vulnerability.

Long-Term Security Practices

Regularly monitor and apply security updates for all software dependencies to prevent the exploitation of known vulnerabilities.
Implement secure coding practices and conduct thorough security testing, including fuzz testing, to identify and address potential vulnerabilities early.

Patching and Updates

Stay informed about security advisories and patches released by the pdfio library maintainer (Michael Sweet) to address vulnerabilities promptly.
Adopt a proactive approach to system maintenance and update vulnerable components to maintain a secure software environment.