CVE-2021-20236 (GCVE-0-2021-20236)

Vulnerability from cvelistv5 – Published: 2021-05-28 10:42 – Updated: 2024-08-03 17:37
VLAI
Summary
A flaw was found in the ZeroMQ server in versions before 4.3.3. This flaw allows a malicious client to cause a stack buffer overflow on the server by sending crafted topic subscription requests and then unsubscribing. The highest threat from this vulnerability is to confidentiality, integrity, as well as system availability.
Severity
9.8 (Critical)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CWE
Assigner
redhat CNA under the redhat root
CNA scorecard B 82/100 over 1085 records in the last 180 days details
References
Impacted products
Vendor Product Version CPE status
n/a zeromq Affected: zeromq 4.3.3
Show details on NVD website
To clipboard 

{
  "containers": {
    "adp": [
      {
        "providerMetadata": {
          "dateUpdated": "2024-08-03T17:37:23.102Z",
          "orgId": "af854a3a-2127-422b-91ae-364da2661108",
          "shortName": "CVE"
        },
        "references": [
          {
            "tags": [
              "x_refsource_MISC",
              "x_transferred"
            ],
            "url": "https://bugzilla.redhat.com/show_bug.cgi?id=1921976"
          },
          {
            "tags": [
              "x_refsource_MISC",
              "x_transferred"
            ],
            "url": "https://github.com/zeromq/libzmq/security/advisories/GHSA-qq65-x72m-9wr8"
          }
        ],
        "title": "CVE Program Container"
      }
    ],
    "cna": {
      "affected": [
        {
          "product": "zeromq",
          "vendor": "n/a",
          "versions": [
            {
              "status": "affected",
              "version": "zeromq 4.3.3"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "A flaw was found in the ZeroMQ server in versions before 4.3.3. This flaw allows a malicious client to cause a stack buffer overflow on the server by sending crafted topic subscription requests and then unsubscribing. The highest threat from this vulnerability is to confidentiality, integrity, as well as system availability."
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-120",
              "description": "CWE-120-\u003eCWE-787",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2021-05-28T10:42:19.000Z",
        "orgId": "53f830b8-0a3f-465b-8143-3b8a9948e749",
        "shortName": "redhat"
      },
      "references": [
        {
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://bugzilla.redhat.com/show_bug.cgi?id=1921976"
        },
        {
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/zeromq/libzmq/security/advisories/GHSA-qq65-x72m-9wr8"
        }
      ],
      "x_legacyV4Record": {
        "CVE_data_meta": {
          "ASSIGNER": "secalert@redhat.com",
          "ID": "CVE-2021-20236",
          "STATE": "PUBLIC"
        },
        "affects": {
          "vendor": {
            "vendor_data": [
              {
                "product": {
                  "product_data": [
                    {
                      "product_name": "zeromq",
                      "version": {
                        "version_data": [
                          {
                            "version_value": "zeromq 4.3.3"
                          }
                        ]
                      }
                    }
                  ]
                },
                "vendor_name": "n/a"
              }
            ]
          }
        },
        "data_format": "MITRE",
        "data_type": "CVE",
        "data_version": "4.0",
        "description": {
          "description_data": [
            {
              "lang": "eng",
              "value": "A flaw was found in the ZeroMQ server in versions before 4.3.3. This flaw allows a malicious client to cause a stack buffer overflow on the server by sending crafted topic subscription requests and then unsubscribing. The highest threat from this vulnerability is to confidentiality, integrity, as well as system availability."
            }
          ]
        },
        "problemtype": {
          "problemtype_data": [
            {
              "description": [
                {
                  "lang": "eng",
                  "value": "CWE-120-\u003eCWE-787"
                }
              ]
            }
          ]
        },
        "references": {
          "reference_data": [
            {
              "name": "https://bugzilla.redhat.com/show_bug.cgi?id=1921976",
              "refsource": "MISC",
              "url": "https://bugzilla.redhat.com/show_bug.cgi?id=1921976"
            },
            {
              "name": "https://github.com/zeromq/libzmq/security/advisories/GHSA-qq65-x72m-9wr8",
              "refsource": "MISC",
              "url": "https://github.com/zeromq/libzmq/security/advisories/GHSA-qq65-x72m-9wr8"
            }
          ]
        }
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "53f830b8-0a3f-465b-8143-3b8a9948e749",
    "assignerShortName": "redhat",
    "cveId": "CVE-2021-20236",
    "datePublished": "2021-05-28T10:42:19.000Z",
    "dateReserved": "2020-12-17T00:00:00.000Z",
    "dateUpdated": "2024-08-03T17:37:23.102Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.1",
  "vulnerability-lookup:meta": {
    "epss": {
      "cve": "CVE-2021-20236",
      "date": "2026-10-31",
      "epss": "0.01868",
      "percentile": "0.79321"
    },
    "microsoft_vex": {
      "current_release_date": "2021-06-03T00:00:00.000Z",
      "cve": "CVE-2021-20236",
      "id": "msrc_CVE-2021-20236",
      "initial_release_date": "2021-05-02T00:00:00.000Z",
      "product_status:fixed": "1",
      "product_status:known_affected": "1",
      "source": "Microsoft CSAF VEX",
      "status": "final",
      "title": "A flaw was found in the ZeroMQ server in versions before 4.3.3. This flaw allows a malicious client to cause a stack buffer overflow on the server by sending crafted topic subscription requests and then unsubscribing. The highest threat from this vulnerability is to confidentiality integrity as well as system availability.",
      "url": "https://msrc.microsoft.com/csaf/vex/2021/msrc_cve-2021-20236.json",
      "version": "1"
    },
    "nvd": {
      "cve": {
        "configurations": [
          {
            "nodes": [
              {
                "cpeMatch": [
                  {
                    "criteria": "cpe:2.3:a:zeromq:zeromq:*:*:*:*:*:*:*:*",
                    "matchCriteriaId": "BD0413A2-9EC5-49F3-ACE6-3E5922F67FB1",
                    "versionEndExcluding": "4.3.3",
                    "vulnerable": true
                  }
                ],
                "negate": false,
                "operator": "OR"
              }
            ]
          },
          {
            "nodes": [
              {
                "cpeMatch": [
                  {
                    "criteria": "cpe:2.3:a:redhat:ceph_storage:2.0:*:*:*:*:*:*:*",
                    "matchCriteriaId": "D07DF15E-FE6B-4DAF-99BB-2147CF7D7EEA",
                    "vulnerable": true
                  },
                  {
                    "criteria": "cpe:2.3:o:redhat:enterprise_linux:7.0:*:*:*:*:*:*:*",
                    "matchCriteriaId": "142AD0DD-4CF3-4D74-9442-459CE3347E3A",
                    "vulnerable": true
                  }
                ],
                "negate": false,
                "operator": "OR"
              }
            ]
          },
          {
            "nodes": [
              {
                "cpeMatch": [
                  {
                    "criteria": "cpe:2.3:o:fedoraproject:fedora:33:*:*:*:*:*:*:*",
                    "matchCriteriaId": "E460AA51-FCDA-46B9-AE97-E6676AA5E194",
                    "vulnerable": true
                  }
                ],
                "negate": false,
                "operator": "OR"
              }
            ]
          }
        ],
        "cveTags": [],
        "descriptions": [
          {
            "lang": "en",
            "value": "A flaw was found in the ZeroMQ server in versions before 4.3.3. This flaw allows a malicious client to cause a stack buffer overflow on the server by sending crafted topic subscription requests and then unsubscribing. The highest threat from this vulnerability is to confidentiality, integrity, as well as system availability."
          },
          {
            "lang": "es",
            "value": "Se encontr\u00f3 un fallo en el servidor ZeroMQ en versiones anteriores a 4.3.3.\u0026#xa0;Este fallo permite a un cliente malicioso causar un desbordamiento del b\u00fafer de pila en el servidor mediante el env\u00edo de peticiones de suscripci\u00f3n de temas dise\u00f1adas y luego cancelando la suscripci\u00f3n.\u0026#xa0;La mayor amenaza de esta vulnerabilidad es la confidencialidad, la integridad y la disponibilidad del sistema"
          }
        ],
        "id": "CVE-2021-20236",
        "lastModified": "2024-11-21T05:46:11.350",
        "metrics": {
          "cvssMetricV2": [
            {
              "acInsufInfo": false,
              "baseSeverity": "HIGH",
              "cvssData": {
                "accessComplexity": "LOW",
                "accessVector": "NETWORK",
                "authentication": "NONE",
                "availabilityImpact": "PARTIAL",
                "baseScore": 7.5,
                "confidentialityImpact": "PARTIAL",
                "integrityImpact": "PARTIAL",
                "vectorString": "AV:N/AC:L/Au:N/C:P/I:P/A:P",
                "version": "2.0"
              },
              "exploitabilityScore": 10.0,
              "impactScore": 6.4,
              "obtainAllPrivilege": false,
              "obtainOtherPrivilege": false,
              "obtainUserPrivilege": false,
              "source": "nvd@nist.gov",
              "type": "Primary",
              "userInteractionRequired": false
            }
          ],
          "cvssMetricV31": [
            {
              "cvssData": {
                "attackComplexity": "LOW",
                "attackVector": "NETWORK",
                "availabilityImpact": "HIGH",
                "baseScore": 9.8,
                "baseSeverity": "CRITICAL",
                "confidentialityImpact": "HIGH",
                "integrityImpact": "HIGH",
                "privilegesRequired": "NONE",
                "scope": "UNCHANGED",
                "userInteraction": "NONE",
                "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
                "version": "3.1"
              },
              "exploitabilityScore": 3.9,
              "impactScore": 5.9,
              "source": "nvd@nist.gov",
              "type": "Primary"
            }
          ]
        },
        "published": "2021-05-28T11:15:07.933",
        "references": [
          {
            "source": "secalert@redhat.com",
            "tags": [
              "Issue Tracking",
              "Third Party Advisory"
            ],
            "url": "https://bugzilla.redhat.com/show_bug.cgi?id=1921976"
          },
          {
            "source": "secalert@redhat.com",
            "tags": [
              "Patch",
              "Third Party Advisory"
            ],
            "url": "https://github.com/zeromq/libzmq/security/advisories/GHSA-qq65-x72m-9wr8"
          },
          {
            "source": "af854a3a-2127-422b-91ae-364da2661108",
            "tags": [
              "Issue Tracking",
              "Third Party Advisory"
            ],
            "url": "https://bugzilla.redhat.com/show_bug.cgi?id=1921976"
          },
          {
            "source": "af854a3a-2127-422b-91ae-364da2661108",
            "tags": [
              "Patch",
              "Third Party Advisory"
            ],
            "url": "https://github.com/zeromq/libzmq/security/advisories/GHSA-qq65-x72m-9wr8"
          }
        ],
        "sourceIdentifier": "secalert@redhat.com",
        "vulnStatus": "Modified",
        "weaknesses": [
          {
            "description": [
              {
                "lang": "en",
                "value": "CWE-120"
              }
            ],
            "source": "secalert@redhat.com",
            "type": "Secondary"
          },
          {
            "description": [
              {
                "lang": "en",
                "value": "CWE-787"
              }
            ],
            "source": "nvd@nist.gov",
            "type": "Primary"
          }
        ]
      }
    },
    "redhat_vex": {
      "aggregate_severity": "Moderate",
      "current_release_date": "2026-06-26T19:51:24+00:00",
      "cve": "CVE-2021-20236",
      "id": "CVE-2021-20236",
      "initial_release_date": "2021-01-01T00:00:00+00:00",
      "product_status:known_affected": "1",
      "source": "Red Hat CSAF VEX",
      "status": "final",
      "title": "zeromq: Stack overflow on server running PUB/XPUB socket",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2021/cve-2021-20236.json",
      "version": "3"
    }
  }
}



Log in or create an account to share your comment.




Tags
Taxonomy of the tags.




Drag nodes to arrange them. Double-click a related vulnerability to open it, or a source to visit its link. The Physics button on the left tunes the layout and the simulation; the legend at the bottom left hides or shows nodes by kind and by sighting type.

Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

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.
Vulnerability timeline

Sightings and recorded dates, grouped by day · UTC

JSON

Loading timeline…




    Related by attack behaviour

    Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.