TOCTOU Race Condition in boneIO

{
  "id": "70974a13d9516b2ca21053759749952b7d6d1c5d56aadcfc2891f31ed2cdc987",
  "url": "https://www.cve.org/CVERecord?id=CVE-2026-77059",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "TOCTOU Race Condition in boneIO",
    "summary": "boneIO Black contains a TOCTOU race condition in the create_timedatectl_sudoers_file() function in boneio/webui/routes/timezone_sudoers.py. The function writes sudoers rules to a predictable temporary file, validates them, then installs them with root privileges. A local attacker can exploit the race window between validation and installation to substitute malicious content, or use the predictable filename for symlink attacks, resulting in arbitrary sudoers rule injection and local privilege escalation to root. This issue was fixed in version 1.6.0.",
    "evidence": "cve:CVE-2026-77059",
    "products": [
      {
        "name": {
          "value": "boneIO",
          "evidence": "/containers/cna/affected/0/product"
        },
        "prerequisites": [],
        "fixed_versions": [],
        "affected_versions": []
      }
    ],
    "severity": "high",
    "structured": {
      "id": "CVE-2026-77059",
      "aliases": [
        "CVE-2026-77059"
      ],
      "metrics": [
        {
          "format": "CVSS",
          "cvssV4_0": {
            "Safety": "NOT_DEFINED",
            "version": "4.0",
            "Recovery": "NOT_DEFINED",
            "baseScore": 8.8,
            "Automatable": "NOT_DEFINED",
            "attackVector": "LOCAL",
            "baseSeverity": "HIGH",
            "valueDensity": "NOT_DEFINED",
            "vectorString": "CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H",
            "exploitMaturity": "NOT_DEFINED",
            "providerUrgency": "NOT_DEFINED",
            "userInteraction": "NONE",
            "attackComplexity": "LOW",
            "attackRequirements": "PRESENT",
            "privilegesRequired": "LOW",
            "subIntegrityImpact": "HIGH",
            "vulnIntegrityImpact": "HIGH",
            "subAvailabilityImpact": "HIGH",
            "vulnAvailabilityImpact": "HIGH",
            "subConfidentialityImpact": "HIGH",
            "vulnConfidentialityImpact": "HIGH",
            "vulnerabilityResponseEffort": "NOT_DEFINED"
          },
          "scenarios": [
            {
              "lang": "en",
              "value": "GENERAL"
            }
          ]
        }
      ],
      "affected": [
        {
          "repo": "https://github.com/boneIO-eu/app_black",
          "vendor": "boneIO",
          "modules": [
            "app_black",
            "create_timedatectl_sudoers_file()"
          ],
          "product": "boneIO",
          "versions": [
            {
              "status": "affected",
              "version": "1.3.0",
              "lessThan": "1.6.0",
              "versionType": "semver"
            }
          ],
          "packageName": "boneio",
          "programFiles": [
            "boneio/webui/routes/timezone_sudoers.py"
          ],
          "collectionURL": "https://pypi.python.org",
          "defaultStatus": "unaffected",
          "programRoutines": [
            {
              "name": "create_timedatectl_sudoers_file"
            }
          ]
        }
      ],
      "modified": "2026-10-26T15:35:50.139Z",
      "provider": "cve",
      "references": [
        "https://cert.pl/en/posts/2026/10/CVE-2026-77052",
        "https://boneio.eu/en/docs/black"
      ],
      "provider_metadata": {
        "adp": [
          {
            "title": "CISA ADP Vulnrichment",
            "metrics": [
              {
                "other": {
                  "type": "ssvc",
                  "content": {
                    "id": "CVE-2026-77059",
                    "role": "CISA Coordinator",
                    "options": [
                      {
                        "Exploitation": "none"
                      },
                      {
                        "Automatable": "no"
                      },
                      {
                        "Technical Impact": "total"
                      }
                    ],
                    "version": "2.0.3",
                    "timestamp": "2026-10-26T15:30:38.399015Z"
                  }
                }
              }
            ],
            "providerMetadata": {
              "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
              "shortName": "CISA-ADP",
              "dateUpdated": "2026-10-26T15:35:50.139Z"
            }
          }
        ],
        "cna": {
          "orgId": "4bb8329e-dd38-46c1-aafb-9bf32bcb93c6",
          "shortName": "CERT-PL",
          "dateUpdated": "2026-10-26T14:46:02.659Z"
        }
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-77059",
        "evidence": "/cveMetadata/cveId"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/containers/cna/metrics"
  },
  "source_id": "core-cve",
  "document_id": 316060,
  "published_at": "2026-10-26T14:46:02.659+00:00"
}