CVE-2023-36810

PyPDF quadratic runtime vulnerability

• CVSS 6.5
• CWE-407 Inefficient Algorithmic Complexity
• Resource Management
• Remote

pypdf is a pure-python PDF library capable of splitting, merging, cropping, and transforming the pages of PDF files. An attacker who uses this vulnerability can craft a PDF which leads to unexpected long runtime. This quadratic runtime blocks the current process and can utilize a single core of the CPU by 100%. It does not affect memory usage. This issue has been addressed in PR 808 and versions from 1.27.9 include this fix. Users are advised to upgrade. There are no known workarounds for this vulnerability.

CVE

CVE-2023-36810

CWE

CWE-407 Inefficient Algorithmic Complexity

CVSS base score

6.5

Published

2023-06-30

OWASP

A06 Vulnerable and Outdated Components

Orthogonal defect classification

Timing/Serialization

Code defect classification

Timing Issues

Category

Resource Management

Subcategory

Resource Exhaustion

Accessibility scope

Remote

Impact

Denial of Service (DoS)

Fixed by upgrading

Yes

Solution

Update pypdf to version 1.27.9 or higher.

import pypdf

def pdf_processing(pdf_path):
    with open(pdf_path, "rb") as file:
        reader = pypdf.PdfReader(file)
        
        for i in range(len(reader.pages)):
            for j in range(len(reader.pages)):
                page = reader.pages[i]
                text = page.extract_text()
                print(text)

pdf_processing("example.pdf")

import pypdf

def pdf_processing(pdf_path):
    try:
        with open(pdf_path, "rb") as file:
            reader = pypdf.PdfReader(file)

            for i, page in enumerate(reader.pages):
                try:
                    text = page.extract_text()
                    if text:
                        print(f"Page {i + 1}:\n{text}")
                    else:
                        print(f"Page {i + 1}: No text found.")
                except Exception as e:
                    print(f"Error extracting text from page {i + 1}: {e}")
    except (FileNotFoundError, IOError) as file_error:
        print(f"File error: {file_error}")
    except Exception as e:
        print(f"Failed to process PDF: {e}")

@misc{vaitp:cve202336810,
  title        = {{PyPDF quadratic runtime vulnerability}},
  author       = {Bogaerts, Fr\'ed\'eric and Ivaki, Naghmeh and Fonseca, Jos\'e},
  year         = {2023},
  note         = {VAITP Python Vulnerability Dataset, entry CVE-2023-36810},
  howpublished = {\url{https://netpack.pt/vaitp/vulnerability/CVE-2023-36810/}}
}