title: Infinite Loop when a comment isn't followed by a character in pypdf
description: pypdf is an open source, pure-python PDF library. In affected versions an attacker may craft a PDF which leads to an infinite loop if `__parse_content_stream` is executed. That is, for example, the case if the user extracted text from such a PDF. This issue was introduced in pull request #969 and resolved in pull request #1828. Users are advised to upgrade. Users unable to upgrade may modify the line `while peek not in (b"\r", b"\n")` in `pypdf/generic/_data_structures.py` to `while peek not in (b"\r", b"\n", b"")`.
problem types: CWE-835: Loop with Unreachable Exit Condition ('Infinite Loop')
affected:
{
vendor: py-pdf
product: pypdf
versions:
version:  pypdf: < 3.90, status: affected
version: PyPDF2: >= 2.2.0, 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
]