« Back to list

CVE-2020-36323

Status: ModifiedHigh (8.2)—

In the standard library in Rust before 1.52.0, there is an optimization for joining strings that can cause uninitialized bytes to be exposed (or the program to crash) if the borrowed string changes after its length is checked.

CVSS

Exploitation probability (EPSS)

EPSS (Exploit Prediction Scoring System, FIRST) estimates how likely a vulnerability is to be exploited in the wild within 30 days. It complements CVSS (impact) and CISA KEV (confirmed exploitation).

Affected technologies (2)

Fedoraproject — FedoraRust-lang — Rust

CWEs

References

Raw JSON (NVD)

Show
{
  "id": "CVE-2020-36323",
  "cveTags": [],
  "metrics": {
    "cvssMetricV2": [
      {
        "type": "Primary",
        "source": "nvd@nist.gov",
        "cvssData": {
          "version": "2.0",
          "baseScore": 6.4,
          "accessVector": "NETWORK",
          "vectorString": "AV:N/AC:L/Au:N/C:P/I:N/A:P",
          "authentication": "NONE",
          "integrityImpact": "NONE",
          "accessComplexity": "LOW",
          "availabilityImpact": "PARTIAL",
          "confidentialityImpact": "PARTIAL"
        },
        "acInsufInfo": false,
        "impactScore": 4.9,
        "baseSeverity": "MEDIUM",
        "obtainAllPrivilege": false,
        "exploitabilityScore": 10,
        "obtainUserPrivilege": false,
        "obtainOtherPrivilege": false,
        "userInteractionRequired": false
      }
    ],
    "cvssMetricV31": [
      {
        "type": "Primary",
        "source": "nvd@nist.gov",
        "cvssData": {
          "scope": "UNCHANGED",
          "version": "3.1",
          "baseScore": 8.2,
          "attackVector": "NETWORK",
          "baseSeverity": "HIGH",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:H",
          "integrityImpact": "NONE",
          "userInteraction": "NONE",
          "attackComplexity": "LOW",
          "availabilityImpact": "HIGH",
          "privilegesRequired": "NONE",
          "confidentialityImpact": "LOW"
        },
        "impactScore": 4.2,
        "exploitabilityScore": 3.9
      }
    ]
  },
  "affected": [
    {
      "source": "cve@mitre.org",
      "affectedData": [
        {
          "vendor": "n/a",
          "product": "n/a",
          "versions": [
            {
              "status": "affected",
              "version": "n/a"
            }
          ]
        }
      ]
    }
  ],
  "published": "2021-04-14T07:15:12.087",
  "references": [
    {
      "url": "https://github.com/rust-lang/rust/issues/80335",
      "tags": [
        "Patch",
        "Third Party Advisory"
      ],
      "source": "cve@mitre.org"
    },
    {
      "url": "https://github.com/rust-lang/rust/pull/81728",
      "tags": [
        "Patch",
        "Third Party Advisory"
      ],
      "source": "cve@mitre.org"
    },
    {
      "url": "https://github.com/rust-lang/rust/pull/81728#issuecomment-821549174",
      "tags": [
        "Patch",
        "Third Party Advisory"
      ],
      "source": "cve@mitre.org"
    },
    {
      "url": "https://github.com/rust-lang/rust/pull/81728#issuecomment-824904190",
      "tags": [
        "Patch",
        "Third Party Advisory"
      ],
      "source": "cve@mitre.org"
    },
    {
      "url": "https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/CZ337CM4GFJLRDFVQCGC7J25V65JXOG5/",
      "source": "cve@mitre.org"
    },
    {
      "url": "https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/TFUO3URYCO73D2Q4WYJBWAMJWGGVXQO4/",
      "source": "cve@mitre.org"
    },
    {
      "url": "https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/VZG65GUW6Z2CYOQHF7T3TB5CZKIX6ZJE/",
      "source": "cve@mitre.org"
    },
    {
      "url": "https://github.com/rust-lang/rust/issues/80335",
      "tags": [
        "Patch",
        "Third Party Advisory"
      ],
      "source": "af854a3a-2127-422b-91ae-364da2661108"
    },
    {
      "url": "https://github.com/rust-lang/rust/pull/81728",
      "tags": [
        "Patch",
        "Third Party Advisory"
      ],
      "source": "af854a3a-2127-422b-91ae-364da2661108"
    },
    {
      "url": "https://github.com/rust-lang/rust/pull/81728#issuecomment-821549174",
      "tags": [
        "Patch",
        "Third Party Advisory"
      ],
      "source": "af854a3a-2127-422b-91ae-364da2661108"
    },
    {
      "url": "https://github.com/rust-lang/rust/pull/81728#issuecomment-824904190",
      "tags": [
        "Patch",
        "Third Party Advisory"
      ],
      "source": "af854a3a-2127-422b-91ae-364da2661108"
    },
    {
      "url": "https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/CZ337CM4GFJLRDFVQCGC7J25V65JXOG5/",
      "source": "af854a3a-2127-422b-91ae-364da2661108"
    },
    {
      "url": "https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/TFUO3URYCO73D2Q4WYJBWAMJWGGVXQO4/",
      "source": "af854a3a-2127-422b-91ae-364da2661108"
    },
    {
      "url": "https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/VZG65GUW6Z2CYOQHF7T3TB5CZKIX6ZJE/",
      "source": "af854a3a-2127-422b-91ae-364da2661108"
    }
  ],
  "vulnStatus": "Modified",
  "weaknesses": [
    {
      "type": "Primary",
      "source": "nvd@nist.gov",
      "description": [
        {
          "lang": "en",
          "value": "CWE-134"
        }
      ]
    }
  ],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the standard library in Rust before 1.52.0, there is an optimization for joining strings that can cause uninitialized bytes to be exposed (or the program to crash) if the borrowed string changes after its length is checked."
    },
    {
      "lang": "es",
      "value": "En la biblioteca standard en Rust versiones anteriores a 1.52.0, se presenta una optimización para unir cadenas que pueden causar que los bytes no inicializados queden expuestos (o que el programa se bloquee) si la cadena prestada cambia después de que su longitud es comprobada"
    }
  ],
  "lastModified": "2026-06-17T03:15:18.443",
  "configurations": [
    {
      "nodes": [
        {
          "negate": false,
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:a:rust-lang:rust:*:*:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "8E9A2A10-536D-4719-9D35-637A525E1E04",
              "versionEndExcluding": "1.52.0"
            }
          ],
          "operator": "OR"
        }
      ]
    },
    {
      "nodes": [
        {
          "negate": false,
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:o:fedoraproject:fedora:32:*:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "36D96259-24BD-44E2-96D9-78CE1D41F956"
            },
            {
              "criteria": "cpe:2.3:o:fedoraproject:fedora:33:*:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "E460AA51-FCDA-46B9-AE97-E6676AA5E194"
            },
            {
              "criteria": "cpe:2.3:o:fedoraproject:fedora:34:*:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "A930E247-0B43-43CB-98FF-6CE7B8189835"
            }
          ],
          "operator": "OR"
        }
      ]
    }
  ],
  "sourceIdentifier": "cve@mitre.org"
}