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GHSA-4VVM-4W3V-6MR8

Vulnerability from github – Published: 2023-06-30 20:33 – Updated: 2023-07-07 17:19
VLAI
Summary
pypdf and PyPDF2 possible Infinite Loop when a comment isn't followed by a character
Details

Impact

An attacker who uses this vulnerability can craft a PDF which leads to an infinite loop if __parse_content_stream is executed. This infinite loop blocks the current process and can utilize a single core of the CPU by 100%. It does not affect memory usage. That is, for example, the case if the user extracted text from such a PDF.

Example Code and a PDF that causes the issue:

from pypdf import PdfReader

# https://objects.githubusercontent.com/github-production-repository-file-5c1aeb/3119517/11367871?X-Amz-Algorithm=AWS4-HMAC-SHA256&X-Amz-Credential=AKIAIWNJYAX4CSVEH53A%2F20230627%2Fus-east-1%2Fs3%2Faws4_request&X-Amz-Date=20230627T201018Z&X-Amz-Expires=300&X-Amz-Signature=d71c8fd9181c4875f0c04d563b6d32f1d4da6e7b2e6be2f14479ce4ecdc9c8b2&X-Amz-SignedHeaders=host&actor_id=1658117&key_id=0&repo_id=3119517&response-content-disposition=attachment%3Bfilename%3DMiFO_LFO_FEIS_NOA_Published.3.pdf&response-content-type=application%2Fpdf
reader = PdfReader("MiFO_LFO_FEIS_NOA_Published.3.pdf")
page = reader.pages[0]
page.extract_text()

The issue was introduced with https://github.com/py-pdf/pypdf/pull/969

Patches

The issue was fixed with https://github.com/py-pdf/pypdf/pull/1828

Workarounds

It is recommended to upgrade to pypdf>=3.9.0. PyPDF2 users should migrate to pypdf.

If you cannot update your version of pypdf, you should modify pypdf/generic/_data_structures.py:

OLD: while peek not in (b"\r", b"\n"):
NEW: while peek not in (b"\r", b"\n", b""):
Severity
6.2 (Medium)
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Show details on source website
To clipboard 

{
  "affected": [
    {
      "package": {
        "ecosystem": "PyPI",
        "name": "pypdf"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "3.1.0"
            },
            {
              "fixed": "3.9.0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "PyPI",
        "name": "PyPDF2"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "2.2.0"
            },
            {
              "last_affected": "3.0.1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2023-36464"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-835"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2023-06-30T20:33:57Z",
    "nvd_published_at": "2023-06-27T22:15:11Z",
    "severity": "MODERATE"
  },
  "details": "### Impact\nAn attacker who uses this vulnerability can craft a PDF which leads to an infinite loop if `__parse_content_stream` is executed. This infinite loop blocks the current process and can utilize a single core of the CPU by 100%. It does not affect memory usage. That is, for example, the case if the user extracted text from such a PDF.\n\nExample Code and a PDF that causes the issue:\n\n```python\nfrom pypdf import PdfReader\n\n# https://objects.githubusercontent.com/github-production-repository-file-5c1aeb/3119517/11367871?X-Amz-Algorithm=AWS4-HMAC-SHA256\u0026X-Amz-Credential=AKIAIWNJYAX4CSVEH53A%2F20230627%2Fus-east-1%2Fs3%2Faws4_request\u0026X-Amz-Date=20230627T201018Z\u0026X-Amz-Expires=300\u0026X-Amz-Signature=d71c8fd9181c4875f0c04d563b6d32f1d4da6e7b2e6be2f14479ce4ecdc9c8b2\u0026X-Amz-SignedHeaders=host\u0026actor_id=1658117\u0026key_id=0\u0026repo_id=3119517\u0026response-content-disposition=attachment%3Bfilename%3DMiFO_LFO_FEIS_NOA_Published.3.pdf\u0026response-content-type=application%2Fpdf\nreader = PdfReader(\"MiFO_LFO_FEIS_NOA_Published.3.pdf\")\npage = reader.pages[0]\npage.extract_text()\n```\n\nThe issue was introduced with https://github.com/py-pdf/pypdf/pull/969\n\n### Patches\n\nThe issue was fixed with https://github.com/py-pdf/pypdf/pull/1828\n\n### Workarounds\n\nIt is recommended to upgrade to `pypdf\u003e=3.9.0`. PyPDF2 users should migrate to pypdf.\n\nIf you cannot update your version of pypdf, you should modify `pypdf/generic/_data_structures.py`:\n\n```\nOLD: while peek not in (b\"\\r\", b\"\\n\"):\nNEW: while peek not in (b\"\\r\", b\"\\n\", b\"\"):\n```",
  "id": "GHSA-4vvm-4w3v-6mr8",
  "modified": "2023-07-07T17:19:37Z",
  "published": "2023-06-30T20:33:57Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/py-pdf/pypdf/security/advisories/GHSA-4vvm-4w3v-6mr8"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2023-36464"
    },
    {
      "type": "WEB",
      "url": "https://github.com/py-pdf/pypdf/pull/1828"
    },
    {
      "type": "WEB",
      "url": "https://github.com/py-pdf/pypdf/pull/969"
    },
    {
      "type": "WEB",
      "url": "https://github.com/py-pdf/pypdf/commit/b0e5c689df689ab173df84dacd77b6fc3c161932"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/py-pdf/pypdf"
    },
    {
      "type": "WEB",
      "url": "https://github.com/py-pdf/pypdf/releases/tag/3.9.0"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "pypdf and PyPDF2 possible Infinite Loop when a comment isn\u0027t followed by a character"
}



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