Skip to content
Heist/ feed
Back to feed
Critical

Security advisory

Type: advisorySources: OSVCVE: CVE-2021-31873

An issue was discovered in klibc before 2.0.9. Additions in the malloc() function may result in an integer overflow and a subsequent heap buffer overflow.

Products
Not specified
Affected versions
Not specified
Fixed versions
Not specified
CVEs
CVE-2021-31873
Confirmed fixed CVEs
Not specified
Updated in this feed
31 Oct 2026, 12:44 UTC · Revision 1

Source evidence

CVE-2021-31873

core-osv · Original source

Published 30 Apr 2021, 06:15 UTC

An issue was discovered in klibc before 2.0.9. Additions in the malloc() function may result in an integer overflow and a subsequent heap buffer overflow.

osv:CVE-2021-31873
Complete source record
{
  "id": "c265f616d20f6e55e31a76fe96cfcab4baccf153eccbe4213f885d215db43d48",
  "url": "https://osv.dev/vulnerability/CVE-2021-31873",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "CVE-2021-31873",
    "summary": "An issue was discovered in klibc before 2.0.9. Additions in the malloc() function may result in an integer overflow and a subsequent heap buffer overflow.",
    "evidence": "osv:CVE-2021-31873",
    "products": [],
    "severity": "critical",
    "structured": {
      "id": "CVE-2021-31873",
      "aliases": [
        "CVE-2021-31873"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/huolinjue/klibc",
              "type": "GIT",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "2e48a12ab1e30d43498c2d53e878a11a1b5102d5"
                },
                {
                  "fixed": "a31ae8c508fc8d1bca4f57e9f9f88127572d5202"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "cpe": "cpe:2.3:a:klibc_project:klibc:*:*:*:*:*:*:*:*",
                    "range": [
                      {
                        "introduced": "0"
                      },
                      {
                        "fixed": "2.0.9"
                      }
                    ],
                    "source": "CPE_RANGE"
                  },
                  {
                    "range": [
                      {
                        "fixed": "a31ae8c508fc8d1bca4f57e9f9f88127572d5202"
                      }
                    ],
                    "source": "REFERENCES_COMMIT"
                  }
                ]
              }
            }
          ],
          "versions": [
            "klibc-2.0.8",
            "klibc-2.0.7",
            "klibc-2.0.6",
            "klibc-2.0.5",
            "klibc-2.0.4",
            "klibc-2.0.3",
            "klibc-2.0.2",
            "klibc-2.0.1",
            "klibc-2.0",
            "klibc-1.5.25",
            "klibc-1.5.24",
            "klibc-1.5.23",
            "klibc-1.5.22",
            "klibc-1.5.21",
            "klibc-1.5.20",
            "klibc-1.5.19",
            "klibc-1.5.18",
            "klibc-1.5.17",
            "klibc-1.5.16",
            "klibc-1.5.15",
            "klibc-1.5.14",
            "klibc-1.5.13",
            "klibc-1.5.12",
            "klibc-1.5.11",
            "klibc-1.5.10",
            "klibc-1.5.9",
            "klibc-1.5.8",
            "klibc-1.5.7",
            "klibc-1.5.6",
            "klibc-1.5.5",
            "klibc-1.5.4",
            "klibc-1.5.3",
            "klibc-1.5.2",
            "klibc-1.5.1",
            "klibc-1.5",
            "klibc-1.4.39",
            "klibc-1.4.36",
            "klibc-1.4.35",
            "klibc-1.4.34",
            "klibc-1.4.33",
            "klibc-1.4.32",
            "klibc-1.4.31",
            "klibc-1.4.30",
            "klibc-1.4.29",
            "klibc-1.4.28",
            "klibc-1.4.27",
            "klibc-1.4.26",
            "klibc-1.4.25",
            "klibc-1.4.24",
            "klibc-1.4.23",
            "klibc-1.4.22",
            "klibc-1.4.21",
            "klibc-1.4.18",
            "klibc-1.4.17",
            "klibc-1.4.16",
            "klibc-1.4.14",
            "klibc-1.4.13",
            "klibc-1.4.12",
            "klibc-1.4.11",
            "klibc-1.4.10",
            "klibc-1.4.9",
            "klibc-1.4.8",
            "klibc-1.4.7",
            "klibc-1.4.6",
            "klibc-1.4.5",
            "klibc-1.4.4",
            "klibc-1.4.3",
            "klibc-1.4.2",
            "klibc-1.4.1",
            "klibc-1.4",
            "klibc-1.3.40",
            "klibc-1.3.39",
            "klibc-1.3.38",
            "klibc-1.3.37",
            "klibc-1.3.36",
            "klibc-1.3.35",
            "klibc-1.3.34",
            "klibc-1.3.33",
            "klibc-1.3.32",
            "klibc-1.3.31",
            "klibc-1.3.30",
            "klibc-1.3.29",
            "klibc-1.3.28",
            "klibc-1.3.26",
            "klibc-1.3.25",
            "klibc-1.3.24",
            "klibc-1.3.23",
            "klibc-1.3.22",
            "klibc-1.3.21",
            "klibc-1.3.20",
            "klibc-1.3.19",
            "klibc-1.3.18",
            "klibc-1.3.17",
            "klibc-1.3.15",
            "klibc-1.3.14",
            "klibc-1.3.13",
            "klibc-1.3.12",
            "klibc-1.3.11",
            "klibc-1.3.7",
            "klibc-1.3.6",
            "klibc-1.3.3",
            "klibc-1.3.2",
            "klibc-1.3.1",
            "klibc-1.3",
            "klibc-1.2.8",
            "klibc-1.2.7",
            "klibc-1.2.5",
            "klibc-1.2.4",
            "klibc-1.2.3",
            "klibc-1.2.2",
            "klibc-1.2.1",
            "klibc-1.2",
            "klibc-1.1.16",
            "klibc-1.1.15",
            "klibc-1.1.14",
            "klibc-1.1.13",
            "klibc-1.1.12",
            "klibc-1.1.11",
            "klibc-1.1.10",
            "klibc-1.1.9",
            "klibc-1.1.8",
            "klibc-1.1.7",
            "klibc-1.1.6",
            "klibc-1.1.5",
            "klibc-1.1.3",
            "klibc-1.1.2",
            "klibc-1.1.1",
            "klibc-1.0.14",
            "klibc-1.0.13",
            "klibc-1.0.12",
            "klibc-1.0.11",
            "klibc-1.0.10",
            "klibc-1.0.9",
            "klibc-1.0.8",
            "klibc-1.0.7",
            "klibc-1.0.6",
            "klibc-1.0.5",
            "klibc-1.0.4",
            "klibc-1.0.3",
            "klibc-1.0.2",
            "klibc-1.0.1",
            "klibc-1.0",
            "klibc-0.217",
            "klibc-0.216",
            "klibc-0.215",
            "klibc-0.214",
            "klibc-0.213",
            "klibc-0.212",
            "klibc-0.211",
            "klibc-0.210",
            "klibc-0.209",
            "klibc-0.208",
            "klibc-0.207",
            "klibc-0.206",
            "klibc-0.205",
            "klibc-0.204",
            "klibc-0.203",
            "klibc-0.202",
            "klibc-0.201",
            "klibc-0.200",
            "klibc-0.199",
            "klibc-0.198",
            "klibc-0.197",
            "klibc-0.196",
            "klibc-0.195",
            "klibc-0.194",
            "klibc-0.193",
            "klibc-0.192",
            "klibc-0.191",
            "klibc-0.190",
            "klibc-0.189",
            "klibc-0.188",
            "klibc-0.187",
            "klibc-0.186",
            "klibc-0.185",
            "klibc-0.184",
            "klibc-0.183",
            "klibc-0.182",
            "klibc-0.181",
            "klibc-0.180",
            "klibc-0.179",
            "klibc-0.178",
            "klibc-0.177",
            "klibc-0.176",
            "klibc-0.175",
            "klibc-0.174",
            "klibc-0.173",
            "klibc-0.172",
            "klibc-0.171",
            "klibc-0.170",
            "klibc-0.169",
            "klibc-0.168",
            "klibc-0.167",
            "klibc-0.166",
            "klibc-0.165",
            "klibc-0.164",
            "klibc-0.163",
            "klibc-0.162",
            "klibc-0.161",
            "klibc-0.160",
            "klibc-0.159",
            "klibc-0.158",
            "klibc-0.157",
            "klibc-0.156",
            "klibc-0.155",
            "klibc-0.154",
            "klibc-0.153",
            "klibc-0.152",
            "klibc-0.151",
            "klibc-0.150",
            "klibc-0.149",
            "klibc-0.148",
            "klibc-0.147",
            "klibc-0.146",
            "klibc-0.145",
            "klibc-0.144",
            "klibc-0.143",
            "klibc-0.142",
            "klibc-0.141",
            "klibc-0.140",
            "klibc-0.139",
            "klibc-0.138",
            "klibc-0.137",
            "klibc-0.136",
            "klibc-0.135",
            "klibc-0.134",
            "klibc-0.133",
            "klibc-0.132",
            "klibc-0.131",
            "klibc-0.130",
            "klibc-0.129",
            "klibc-0.128",
            "klibc-0.127",
            "klibc-0.126",
            "klibc-0.125",
            "klibc-0.124",
            "klibc-0.123",
            "klibc-0.122",
            "klibc-0.121",
            "klibc-0.120",
            "klibc-0.119",
            "klibc-0.118",
            "klibc-0.117",
            "klibc-0.116",
            "klibc-0.115",
            "klibc-0.114",
            "klibc-0.113",
            "klibc-0.112",
            "klibc-0.111",
            "klibc-0.110",
            "klibc-0.109",
            "klibc-0.108",
            "klibc-0.107",
            "klibc-0.106",
            "klibc-0.105",
            "klibc-0.104",
            "klibc-0.103",
            "klibc-0.102",
            "klibc-0.101",
            "klibc-0.100",
            "klibc-0.99",
            "klibc-0.98",
            "klibc-0.97",
            "klibc-0.96",
            "klibc-0.95",
            "klibc-0.94",
            "klibc-0.93",
            "klibc-0.92",
            "klibc-0.91",
            "klibc-0.90",
            "klibc-0.89",
            "klibc-0.88",
            "klibc-0.87",
            "klibc-0.86",
            "klibc-0.85",
            "klibc-0.84",
            "klibc-0.83",
            "klibc-0.82",
            "klibc-0.81",
            "klibc-0.80",
            "klibc-0.79",
            "klibc-0.78",
            "klibc-0.77",
            "klibc-0.76",
            "klibc-0.75",
            "klibc-0.74",
            "klibc-0.73",
            "klibc-0.72",
            "klibc-0.71",
            "klibc-0.70",
            "klibc-0.69",
            "klibc-0.68",
            "klibc-0.67",
            "klibc-0.65",
            "klibc-0.66",
            "klibc-0.64",
            "klibc-0.63",
            "klibc-0.62",
            "klibc-0.61",
            "klibc-0.60",
            "klibc-0.59",
            "klibc-0.58",
            "klibc-0.57",
            "klibc-0.56",
            "klibc-0.55",
            "klibc-0.53",
            "klibc-0.54",
            "klibc-0.52",
            "klibc-0.51",
            "klibc-0.50",
            "klibc-0.49",
            "klibc-0.47",
            "klibc-0.46",
            "klibc-0.45",
            "klibc-0.43",
            "klibc-0.42",
            "klibc-0.39",
            "klibc-0.40",
            "klibc-0.41",
            "klibc-0.38",
            "klibc-0.37",
            "klibc-0.36",
            "klibc-0.35",
            "klibc-0.34",
            "klibc-0.33",
            "klibc-0.32",
            "klibc-0.31",
            "klibc-0.30",
            "klibc-0.27",
            "klibc-0.28",
            "klibc-0.29",
            "klibc-0.26",
            "klibc-0.25",
            "klibc-0.24",
            "klibc-0.23",
            "klibc-0.22",
            "klibc-0.21",
            "klibc-0.20",
            "klibc-0.18",
            "klibc-0.19",
            "klibc-0.17",
            "klibc-0.16",
            "klibc-0.15",
            "klibc-0.14",
            "klibc-0.13",
            "klibc-0.12",
            "klibc-0.11",
            "klibc-0.10",
            "klibc-0.9",
            "klibc-0.8",
            "klibc-0.7",
            "klibc-0.6",
            "klibc-0.5",
            "klibc-0.4",
            "klibc-0.3",
            "klibc-0.2",
            "klibc-0.1"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2021-31873.json",
            "vanir_signatures": [
              {
                "id": "CVE-2021-31873-72e70cd3",
                "digest": {
                  "threshold": 0.9,
                  "line_hashes": [
                    "308283541531381744514487166056665852727",
                    "185068699135860301733489562560209838802",
                    "132144626656056469567345719663273201775",
                    "47804530823586436168056557717241444302"
                  ]
                },
                "source": "https://github.com/huolinjue/klibc/commit/2e48a12ab1e30d43498c2d53e878a11a1b5102d5",
                "target": {
                  "file": "usr/utils/cpio.c"
                },
                "deprecated": false,
                "signature_type": "Line",
                "signature_version": "v1"
              },
              {
                "id": "CVE-2021-31873-abb2255b",
                "digest": {
                  "length": 697,
                  "function_hash": "272096419306266800040729748449922772828"
                },
                "source": "https://github.com/huolinjue/klibc/commit/2e48a12ab1e30d43498c2d53e878a11a1b5102d5",
                "target": {
                  "file": "usr/utils/cpio.c",
                  "function": "copyin_link"
                },
                "deprecated": false,
                "signature_type": "Function",
                "signature_version": "v1"
              },
              {
                "id": "CVE-2021-31873-b9ffccc1",
                "digest": {
                  "threshold": 0.9,
                  "line_hashes": [
                    "217924328770968556832553208148882712384",
                    "187361156840409739383989126867014420216",
                    "283857668055714559123873115374762873854"
                  ]
                },
                "source": "https://github.com/huolinjue/klibc/commit/a31ae8c508fc8d1bca4f57e9f9f88127572d5202",
                "target": {
                  "file": "usr/klibc/malloc.c"
                },
                "deprecated": false,
                "signature_type": "Line",
                "signature_version": "v1"
              },
              {
                "id": "CVE-2021-31873-d7e0cb41",
                "digest": {
                  "length": 1034,
                  "function_hash": "174256505860084667354504871651983070251"
                },
                "source": "https://github.com/huolinjue/klibc/commit/a31ae8c508fc8d1bca4f57e9f9f88127572d5202",
                "target": {
                  "file": "usr/klibc/malloc.c",
                  "function": "malloc"
                },
                "deprecated": false,
                "signature_type": "Function",
                "signature_version": "v1"
              }
            ],
            "vanir_signatures_modified": "2026-10-20T14:23:44Z"
          }
        }
      ],
      "modified": "2026-10-20T14:23:44.505537401Z",
      "provider": "osv",
      "references": [
        "https://kernel.org/pub/linux/libs/klibc/2.0/",
        "https://lists.debian.org/debian-lts-announce/2021/06/msg00025.html",
        "https://lists.zytor.com/archives/klibc/2021-April/004593.html",
        "https://git.kernel.org/pub/scm/libs/klibc/klibc.git/commit/?id=a31ae8c508fc8d1bca4f57e9f9f88127572d5202",
        "https://github.com/huolinjue/klibc/commit/a31ae8c508fc8d1bca4f57e9f9f88127572d5202"
      ],
      "provider_metadata": {
        "unresolved_ranges": [
          {
            "cpes": [
              "cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:*"
            ],
            "vendor_product": "debian:debian_linux",
            "extracted_events": [
              {
                "range": [
                  {
                    "introduced": "9.0"
                  },
                  {
                    "last_affected": "9.0"
                  }
                ],
                "source": "CPE_STRING"
              }
            ]
          }
        ]
      }
    },
    "related_cves": [
      {
        "value": "CVE-2021-31873",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 388886,
  "published_at": "2021-04-30T06:15:07.343+00:00"
}