Vulnerability-Lookup

RUSTSEC-2025-0020 (GHSA-PPH8-GCV7-4QJ5)

Vulnerability from osv_rustsec – Published: 2025-04-01 12:00 – Updated: 2025-10-28 06:02 – Source website

Summary

Risk of buffer overflow in `PyString::from_object`

Details

PyString::from_object took &str arguments and forwarded them directly to the Python C API without checking for terminating nul bytes. This could lead the Python interpreter to read beyond the end of the &str data and potentially leak contents of the out-of-bounds read (by raising a Python exception containing a copy of the data including the overflow).

In PyO3 0.24.1 this function will now allocate a CString to guarantee a terminating nul bytes. PyO3 0.25 will likely offer an alternative API which takes &CStr arguments.

References

URL

Type

	https://crates.io/crates/pyo3	PACKAGE
	https://rustsec.org/advisories/RUSTSEC-2025-0020.html	ADVISORY
	https://github.com/PyO3/pyo3/issues/5005	REPORT

JSON

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{
  "affected": [
    {
      "database_specific": {
        "categories": [
          "memory-exposure"
        ],
        "cvss": null,
        "informational": null
      },
      "ecosystem_specific": {
        "affected_functions": null,
        "affects": {
          "arch": [],
          "functions": [
            "pyo3::types::PyString::from_object",
            "pyo3::types::PyString::from_object_bound"
          ],
          "os": []
        }
      },
      "package": {
        "ecosystem": "crates.io",
        "name": "pyo3",
        "purl": "pkg:cargo/pyo3"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0.0.0-0"
            },
            {
              "fixed": "0.24.1"
            }
          ],
          "type": "SEMVER"
        }
      ],
      "versions": []
    }
  ],
  "aliases": [
    "GHSA-pph8-gcv7-4qj5"
  ],
  "database_specific": {
    "license": "CC0-1.0"
  },
  "details": "`PyString::from_object` took `\u0026str` arguments and forwarded them directly to the Python C API without checking for terminating nul bytes. This could lead the Python interpreter to read beyond the end of the `\u0026str` data and potentially leak contents of the out-of-bounds read (by raising a Python exception containing a copy of the data including the overflow).\n\nIn PyO3 0.24.1 this function will now allocate a `CString` to guarantee a terminating nul bytes. PyO3 0.25 will likely offer an alternative API which takes `\u0026CStr` arguments.",
  "id": "RUSTSEC-2025-0020",
  "modified": "2025-10-28T06:02:18Z",
  "published": "2025-04-01T12:00:00Z",
  "references": [
    {
      "type": "PACKAGE",
      "url": "https://crates.io/crates/pyo3"
    },
    {
      "type": "ADVISORY",
      "url": "https://rustsec.org/advisories/RUSTSEC-2025-0020.html"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/PyO3/pyo3/issues/5005"
    }
  ],
  "related": [],
  "severity": [],
  "summary": "Risk of buffer overflow in `PyString::from_object`"
}

GHSA-PPH8-GCV7-4QJ5

Vulnerability from github – Published: 2025-04-02 13:19 – Updated: 2025-04-02 13:19

Summary

PyO3 Risk of buffer overflow in `PyString::from_object`

Details

In PyO3 0.24.1 this function will now allocate a CString to guarantee a terminating nul bytes. PyO3 0.25 will likely offer an alternative API which takes &CStr arguments.

Severity

2.9 (Low)


                  
                    CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:P

Show details on source website

JSON

To clipboard

{
  "affected": [
    {
      "package": {
        "ecosystem": "crates.io",
        "name": "pyo3"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0.1.0"
            },
            {
              "fixed": "0.24.1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [],
  "database_specific": {
    "cwe_ids": [
      "CWE-125"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2025-04-02T13:19:19Z",
    "nvd_published_at": null,
    "severity": "LOW"
  },
  "details": "`PyString::from_object` took `\u0026str` arguments and forwarded them directly to the Python C API without checking for terminating nul bytes. This could lead the Python interpreter to read beyond the end of the `\u0026str` data and potentially leak contents of the out-of-bounds read (by raising a Python exception containing a copy of the data including the overflow).\n\nIn PyO3 0.24.1 this function will now allocate a `CString` to guarantee a terminating nul bytes. PyO3 0.25 will likely offer an alternative API which takes `\u0026CStr` arguments.",
  "id": "GHSA-pph8-gcv7-4qj5",
  "modified": "2025-04-02T13:19:19Z",
  "published": "2025-04-02T13:19:19Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/PyO3/pyo3/issues/5005"
    },
    {
      "type": "WEB",
      "url": "https://github.com/PyO3/pyo3/pull/5008"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/PyO3/pyo3"
    },
    {
      "type": "WEB",
      "url": "https://rustsec.org/advisories/RUSTSEC-2025-0020.html"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:P",
      "type": "CVSS_V4"
    }
  ],
  "summary": "PyO3 Risk of buffer overflow in `PyString::from_object`"
}

Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Detection rules are retrieved from Rulezet.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.

Related by attack behaviour

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