CVE-2023-36810

Quadratic runtime with malformed PDF missing xref marker in pypdf

Severity Score

6.5

*CVSS v3.1

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

*Multiple Sources

Exploited in Wild

*KEV

Decision

Track

*SSVC

Descriptions

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.

It was discovered that PyPDF2 incorrectly handled PDF files with certain markers. 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.

*Credits: N/A

CVSS Scores

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

Required

Scope

Unchanged

Confidentiality

None

Integrity

None

Availability

High

Attack Vector

Local

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

None

Integrity

None

Availability

High

Attack Vector

Network

Attack Complexity

Low

Authentication

None

Confidentiality

None

Integrity

None

Availability

Complete

* Common Vulnerability Scoring System

SSVC

Decision:Track

Exploitation

None

Automatable

Tech. Impact

Partial

* Organization's Worst-case Scenario

Timeline

2023-06-27 CVE Reserved
2023-06-30 CVE Published
2025-02-13 CVE Updated
2025-02-13 First Exploit
2025-04-15 EPSS Updated
---------- Exploited in Wild
---------- KEV Due Date

CWE

CWE-407: Inefficient Algorithmic Complexity

CAPEC

References (4)

URL	Tag	Source
https://lists.debian.org/debian-lts-announce/2023/07/msg00019.html

URL	Date	SRC
https://github.com/py-pdf/pypdf/issues/582	2025-02-13
https://github.com/py-pdf/pypdf/security/advisories/GHSA-jrm6-h9cq-8gqw	2025-02-13

URL	Date	SRC
https://github.com/py-pdf/pypdf/pull/808	2023-07-14

URL	Date	SRC

Affected Vendors, Products, and Versions

Vendor		Product				Version		Other		Status
Vendor	Product	Version	Other	Status	<-- -->	Vendor	Product	Version	Other	Status
Pypdf Project Search vendor "Pypdf Project"		Pypdf Search vendor "Pypdf Project" for product "Pypdf"				<= 1.27.8 Search vendor "Pypdf Project" for product "Pypdf" and version " <= 1.27.8"		-		Affected