CVE-2022-24859 : Exploit Details and Defense Strategies

This article provides insights into CVE-2022-24859, a vulnerability in PyPDF2 that could lead to an Infinite Loop due to manipulated inline images.

Understanding CVE-2022-24859

PyPDF2, a Python PDF library, prior to version 1.27.5, allows an attacker to create a PDF file that triggers an infinite loop when attempting to retrieve the content stream.

What is CVE-2022-24859?

The vulnerability in PyPDF2 arises from an issue in the

_readInlineImage

function where the loop fails to check if the stream has ended, resulting in an endless loop.

The Impact of CVE-2022-24859

This vulnerability could be exploited by an attacker to craft malicious PDF files that cause a denial of service (DoS) condition by consuming excessive system resources.

Technical Details of CVE-2022-24859

Below are the technical aspects of CVE-2022-24859:

Vulnerability Description

In versions prior to 1.27.5, PyPDF2 allows an infinite loop due to a missing check in the

ContentStream._readInlineImage

function.

Affected Systems and Versions

Vendor: py-pdf Product: PyPDF2 Affected Versions: < 1.27.5

Exploitation Mechanism

Attackers can exploit this vulnerability by creating a specially crafted PDF file that triggers the infinite loop condition when parsing the content stream.

Mitigation and Prevention

To secure systems against CVE-2022-24859, the following steps are recommended:

Immediate Steps to Take

Upgrade PyPDF2 to version 1.27.5 or later.
Validate PDF files before processing their content streams to avoid potential exploitation.

Long-Term Security Practices

Regularly update software and libraries to the latest patched versions.
Implement code review and testing to identify and address vulnerabilities.

Patching and Updates

Ensure timely application of patches and updates released by PyPDF2 to address security issues and enhance system resilience.