{
  "schema_version": "1.4.0",
  "id": "GHSA-w7pp-m8wf-vj6r",
  "modified": "2024-09-13T20:07:50Z",
  "published": "2023-02-07T20:54:10Z",
  "aliases": [
    "CVE-2023-23931"
  ],
  "summary": "Cipher.update_into can corrupt memory if passed an immutable python object as the outbuf",
  "details": "Previously, `Cipher.update_into` would accept Python objects which implement the buffer protocol, but provide only immutable buffers:\n\n```pycon\n>>> outbuf = b\"\\x00\" * 32\n>>> c = ciphers.Cipher(AES(b\"\\x00\" * 32), modes.ECB()).encryptor()\n>>> c.update_into(b\"\\x00\" * 16, outbuf)\n16\n>>> outbuf\nb'\\xdc\\x95\\xc0x\\xa2@\\x89\\x89\\xadH\\xa2\\x14\\x92\\x84 \\x87\\x00\\x00\\x00\\x00\\x00\\x00\\x00\\x00\\x00\\x00\\x00\\x00\\x00\\x00\\x00\\x00'\n```\n\nThis would allow immutable objects (such as `bytes`) to be mutated, thus violating fundamental rules of Python. This is a soundness bug -- it allows programmers to misuse an API, it cannot be exploited by attacker controlled data alone.\n\nThis now correctly raises an exception.\n\nThis issue has been present since `update_into` was originally introduced in cryptography 1.8.",
  "severity": [
    {
      "type": "CVSS_V3",
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:L"
    },
    {
      "type": "CVSS_V4",
      "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:L/SC:N/SI:N/SA:N"
    }
  ],
  "affected": [
    {
      "package": {
        "ecosystem": "PyPI",
        "name": "cryptography"
      },
      "ranges": [
        {
          "type": "ECOSYSTEM",
          "events": [
            {
              "introduced": "1.8"
            },
            {
              "fixed": "39.0.1"
            }
          ]
        }
      ]
    }
  ],
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/pyca/cryptography/security/advisories/GHSA-w7pp-m8wf-vj6r"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2023-23931"
    },
    {
      "type": "WEB",
      "url": "https://github.com/pyca/cryptography/pull/8230"
    },
    {
      "type": "WEB",
      "url": "https://github.com/pyca/cryptography/commit/d6951dca25de45abd52da51b608055371fbcde4e"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/pyca/cryptography"
    },
    {
      "type": "WEB",
      "url": "https://github.com/pypa/advisory-database/tree/main/vulns/cryptography/PYSEC-2023-11.yaml"
    }
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-754"
    ],
    "severity": "MODERATE",
    "github_reviewed": true,
    "github_reviewed_at": "2023-02-07T20:54:10Z",
    "nvd_published_at": "2023-02-07T21:15:00Z"
  }
}