Headline
CVE-2022-24859
PyPDF2 is an open source python PDF library capable of splitting, merging, cropping, and transforming the pages of PDF files. In versions prior to 1.27.5 an attacker who uses this vulnerability can craft a PDF which leads to an infinite loop if the PyPDF2 if the code attempts to get the content stream. The reason is that the last while-loop in ContentStream._readInlineImage only terminates when it finds the EI token, but never actually checks if the stream has already ended. This issue has been resolved in version 1.27.5. Users unable to upgrade should validate and PDFs prior to iterating over their content stream.
Manipulated inline images can cause Infinite Loop
Package
pip PyPDF2 (pip )
Affected versions
<=1.27.4
Description
Impact
An attacker who uses this vulnerability can craft a PDF which leads to an infinite loop if the PyPDF2 user wrote the following code:
from PyPDF2 import PdfFileReader, PdfFileWriter from PyPDF2.pdf import ContentStream
reader = PdfFileReader("malicious.pdf", strict=False) for page in reader.pages: ContentStream(page.getContents(), reader)
Patches
PyPDF2==1.27.5 and later are patched.
Credits to Sebastian Krause for finding (issue) and fixing (PR) it.
Related news
Ubuntu Security Notice 6176-1 - It was discovered that PyPDF2 incorrectly handled certain PDF files. If a user or automated system were tricked into processing a specially crafted file, an attacker could possibly use this issue to consume system resources, resulting in a denial of service.