title: Quadratic runtime with malformed PDF missing xref marker in pypdf
description: 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.
problem types: CWE-407: Inefficient Algorithmic Complexity
affected:
{
vendor: py-pdf
product: pypdf
versions:
version: < 1.27.9, status: affected
}
metrics:
cvssV3_1: [
attackComplexity: LOW
attackVector: LOCAL
availabilityImpact: HIGH
baseScore: 6.2
baseSeverity: MEDIUM
confidentialityImpact: NONE
integrityImpact: NONE
privilegesRequired: NONE
scope: UNCHANGED
userInteraction: NONE
vectorString: CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
version: 3.1
]