GCVE Workshop - 22 September 2026 (14:00-18:00), Luxembourg Before The Vulnopticon Conference - Registration

CVE-2021-46823 (GCVE-0-2021-46823)

Vulnerability from cvelistv5 – Published: 2022-06-18 15:27 – Updated: 2024-08-04 05:17
VLAI
Summary
python-ldap before 3.4.0 is vulnerable to a denial of service when ldap.schema is used for untrusted schema definitions, because of a regular expression denial of service (ReDoS) flaw in the LDAP schema parser. By sending crafted regex input, a remote authenticated attacker could exploit this vulnerability to cause a denial of service condition.
Severity
6.5 (Medium)
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
CWE
  • n/a
Assigner
References
Show details on NVD website
To clipboard 

{
  "containers": {
    "adp": [
      {
        "providerMetadata": {
          "dateUpdated": "2024-08-04T05:17:42.836Z",
          "orgId": "af854a3a-2127-422b-91ae-364da2661108",
          "shortName": "CVE"
        },
        "references": [
          {
            "tags": [
              "x_refsource_MISC",
              "x_transferred"
            ],
            "url": "https://github.com/python-ldap/python-ldap/security/advisories/GHSA-r8wq-qrxc-hmcm"
          },
          {
            "tags": [
              "x_refsource_MISC",
              "x_transferred"
            ],
            "url": "https://exchange.xforce.ibmcloud.com/vulnerabilities/221507"
          }
        ],
        "title": "CVE Program Container"
      }
    ],
    "cna": {
      "affected": [
        {
          "product": "n/a",
          "vendor": "n/a",
          "versions": [
            {
              "status": "affected",
              "version": "n/a"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "python-ldap before 3.4.0 is vulnerable to a denial of service when ldap.schema is used for untrusted schema definitions, because of a regular expression denial of service (ReDoS) flaw in the LDAP schema parser. By sending crafted regex input, a remote authenticated attacker could exploit this vulnerability to cause a denial of service condition."
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "description": "n/a",
              "lang": "en",
              "type": "text"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2022-06-18T15:27:17.000Z",
        "orgId": "8254265b-2729-46b6-b9e3-3dfca2d5bfca",
        "shortName": "mitre"
      },
      "references": [
        {
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/python-ldap/python-ldap/security/advisories/GHSA-r8wq-qrxc-hmcm"
        },
        {
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://exchange.xforce.ibmcloud.com/vulnerabilities/221507"
        }
      ],
      "x_legacyV4Record": {
        "CVE_data_meta": {
          "ASSIGNER": "cve@mitre.org",
          "ID": "CVE-2021-46823",
          "STATE": "PUBLIC"
        },
        "affects": {
          "vendor": {
            "vendor_data": [
              {
                "product": {
                  "product_data": [
                    {
                      "product_name": "n/a",
                      "version": {
                        "version_data": [
                          {
                            "version_value": "n/a"
                          }
                        ]
                      }
                    }
                  ]
                },
                "vendor_name": "n/a"
              }
            ]
          }
        },
        "data_format": "MITRE",
        "data_type": "CVE",
        "data_version": "4.0",
        "description": {
          "description_data": [
            {
              "lang": "eng",
              "value": "python-ldap before 3.4.0 is vulnerable to a denial of service when ldap.schema is used for untrusted schema definitions, because of a regular expression denial of service (ReDoS) flaw in the LDAP schema parser. By sending crafted regex input, a remote authenticated attacker could exploit this vulnerability to cause a denial of service condition."
            }
          ]
        },
        "problemtype": {
          "problemtype_data": [
            {
              "description": [
                {
                  "lang": "eng",
                  "value": "n/a"
                }
              ]
            }
          ]
        },
        "references": {
          "reference_data": [
            {
              "name": "https://github.com/python-ldap/python-ldap/security/advisories/GHSA-r8wq-qrxc-hmcm",
              "refsource": "MISC",
              "url": "https://github.com/python-ldap/python-ldap/security/advisories/GHSA-r8wq-qrxc-hmcm"
            },
            {
              "name": "https://exchange.xforce.ibmcloud.com/vulnerabilities/221507",
              "refsource": "MISC",
              "url": "https://exchange.xforce.ibmcloud.com/vulnerabilities/221507"
            }
          ]
        }
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "8254265b-2729-46b6-b9e3-3dfca2d5bfca",
    "assignerShortName": "mitre",
    "cveId": "CVE-2021-46823",
    "datePublished": "2022-06-18T15:27:17.000Z",
    "dateReserved": "2022-06-18T00:00:00.000Z",
    "dateUpdated": "2024-08-04T05:17:42.836Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.1",
  "vulnerability-lookup:meta": {
    "epss": {
      "cve": "CVE-2021-46823",
      "date": "2026-09-20",
      "epss": "0.01897",
      "percentile": "0.78721"
    },
    "fkie_nvd": {
      "configurations": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:a:python-ldap:python-ldap:*:*:*:*:*:*:*:*",
                  "matchCriteriaId": "F835007B-61B5-4D3F-B13B-3AC65B686D7A",
                  "versionEndExcluding": "3.4.0",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "python-ldap before 3.4.0 is vulnerable to a denial of service when ldap.schema is used for untrusted schema definitions, because of a regular expression denial of service (ReDoS) flaw in the LDAP schema parser. By sending crafted regex input, a remote authenticated attacker could exploit this vulnerability to cause a denial of service condition."
        },
        {
          "lang": "es",
          "value": "python-ldap versiones anteriores a 3.4.0, es vulnerable a una denegaci\u00f3n de servicio cuando es usado ldap.schema para definiciones de esquemas que no son confiables, debido a un fallo de denegaci\u00f3n de servicio de expresiones regulares (ReDoS) en el analizador de esquemas LDAP. Al enviar una entrada regex dise\u00f1ada, un atacante remoto autenticado podr\u00eda explotar esta vulnerabilidad para causar una condici\u00f3n de denegaci\u00f3n de servicio"
        }
      ],
      "id": "CVE-2021-46823",
      "lastModified": "2024-11-21T06:34:45.983",
      "metrics": {
        "cvssMetricV2": [
          {
            "acInsufInfo": false,
            "baseSeverity": "MEDIUM",
            "cvssData": {
              "accessComplexity": "LOW",
              "accessVector": "NETWORK",
              "authentication": "SINGLE",
              "availabilityImpact": "PARTIAL",
              "baseScore": 4.0,
              "confidentialityImpact": "NONE",
              "integrityImpact": "NONE",
              "vectorString": "AV:N/AC:L/Au:S/C:N/I:N/A:P",
              "version": "2.0"
            },
            "exploitabilityScore": 8.0,
            "impactScore": 2.9,
            "obtainAllPrivilege": false,
            "obtainOtherPrivilege": false,
            "obtainUserPrivilege": false,
            "source": "nvd@nist.gov",
            "type": "Primary",
            "userInteractionRequired": false
          }
        ],
        "cvssMetricV31": [
          {
            "cvssData": {
              "attackComplexity": "LOW",
              "attackVector": "NETWORK",
              "availabilityImpact": "HIGH",
              "baseScore": 6.5,
              "baseSeverity": "MEDIUM",
              "confidentialityImpact": "NONE",
              "integrityImpact": "NONE",
              "privilegesRequired": "LOW",
              "scope": "UNCHANGED",
              "userInteraction": "NONE",
              "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
              "version": "3.1"
            },
            "exploitabilityScore": 2.8,
            "impactScore": 3.6,
            "source": "nvd@nist.gov",
            "type": "Primary"
          }
        ]
      },
      "published": "2022-06-18T16:15:08.173",
      "references": [
        {
          "source": "cve@mitre.org",
          "tags": [
            "Third Party Advisory",
            "VDB Entry"
          ],
          "url": "https://exchange.xforce.ibmcloud.com/vulnerabilities/221507"
        },
        {
          "source": "cve@mitre.org",
          "tags": [
            "Third Party Advisory"
          ],
          "url": "https://github.com/python-ldap/python-ldap/security/advisories/GHSA-r8wq-qrxc-hmcm"
        },
        {
          "source": "af854a3a-2127-422b-91ae-364da2661108",
          "tags": [
            "Third Party Advisory",
            "VDB Entry"
          ],
          "url": "https://exchange.xforce.ibmcloud.com/vulnerabilities/221507"
        },
        {
          "source": "af854a3a-2127-422b-91ae-364da2661108",
          "tags": [
            "Third Party Advisory"
          ],
          "url": "https://github.com/python-ldap/python-ldap/security/advisories/GHSA-r8wq-qrxc-hmcm"
        }
      ],
      "sourceIdentifier": "cve@mitre.org",
      "vulnStatus": "Modified",
      "weaknesses": [
        {
          "description": [
            {
              "lang": "en",
              "value": "CWE-1333"
            }
          ],
          "source": "nvd@nist.gov",
          "type": "Primary"
        }
      ]
    },
    "microsoft_vex": {
      "current_release_date": "2022-06-29T00:00:00.000Z",
      "cve": "CVE-2021-46823",
      "id": "msrc_CVE-2021-46823",
      "initial_release_date": "2022-06-02T00:00:00.000Z",
      "product_status:fixed": "1",
      "product_status:known_affected": "1",
      "source": "Microsoft CSAF VEX",
      "status": "final",
      "title": "python-ldap before 3.4.0 is vulnerable to a denial of service when ldap.schema is used for untrusted schema definitions because of a regular expression denial of service (ReDoS) flaw in the LDAP schema parser. By sending crafted regex input a remote authenticated attacker could exploit this vulnerability to cause a denial of service condition.",
      "url": "https://msrc.microsoft.com/csaf/vex/2022/msrc_cve-2021-46823.json",
      "version": "1"
    },
    "nvd": {
      "cve": {
        "affected": [
          {
            "affectedData": [
              {
                "product": "n/a",
                "vendor": "n/a",
                "versions": [
                  {
                    "status": "affected",
                    "version": "n/a"
                  }
                ]
              }
            ],
            "source": "cve@mitre.org"
          }
        ],
        "configurations": [
          {
            "nodes": [
              {
                "cpeMatch": [
                  {
                    "criteria": "cpe:2.3:a:python-ldap:python-ldap:*:*:*:*:*:*:*:*",
                    "matchCriteriaId": "F835007B-61B5-4D3F-B13B-3AC65B686D7A",
                    "versionEndExcluding": "3.4.0",
                    "vulnerable": true
                  }
                ],
                "negate": false,
                "operator": "OR"
              }
            ]
          }
        ],
        "cveTags": [],
        "descriptions": [
          {
            "lang": "en",
            "value": "python-ldap before 3.4.0 is vulnerable to a denial of service when ldap.schema is used for untrusted schema definitions, because of a regular expression denial of service (ReDoS) flaw in the LDAP schema parser. By sending crafted regex input, a remote authenticated attacker could exploit this vulnerability to cause a denial of service condition."
          },
          {
            "lang": "es",
            "value": "python-ldap versiones anteriores a 3.4.0, es vulnerable a una denegaci\u00f3n de servicio cuando es usado ldap.schema para definiciones de esquemas que no son confiables, debido a un fallo de denegaci\u00f3n de servicio de expresiones regulares (ReDoS) en el analizador de esquemas LDAP. Al enviar una entrada regex dise\u00f1ada, un atacante remoto autenticado podr\u00eda explotar esta vulnerabilidad para causar una condici\u00f3n de denegaci\u00f3n de servicio"
          }
        ],
        "id": "CVE-2021-46823",
        "lastModified": "2026-06-17T04:15:37.160",
        "metrics": {
          "cvssMetricV2": [
            {
              "acInsufInfo": false,
              "baseSeverity": "MEDIUM",
              "cvssData": {
                "accessComplexity": "LOW",
                "accessVector": "NETWORK",
                "authentication": "SINGLE",
                "availabilityImpact": "PARTIAL",
                "baseScore": 4.0,
                "confidentialityImpact": "NONE",
                "integrityImpact": "NONE",
                "vectorString": "AV:N/AC:L/Au:S/C:N/I:N/A:P",
                "version": "2.0"
              },
              "exploitabilityScore": 8.0,
              "impactScore": 2.9,
              "obtainAllPrivilege": false,
              "obtainOtherPrivilege": false,
              "obtainUserPrivilege": false,
              "source": "nvd@nist.gov",
              "type": "Primary",
              "userInteractionRequired": false
            }
          ],
          "cvssMetricV31": [
            {
              "cvssData": {
                "attackComplexity": "LOW",
                "attackVector": "NETWORK",
                "availabilityImpact": "HIGH",
                "baseScore": 6.5,
                "baseSeverity": "MEDIUM",
                "confidentialityImpact": "NONE",
                "integrityImpact": "NONE",
                "privilegesRequired": "LOW",
                "scope": "UNCHANGED",
                "userInteraction": "NONE",
                "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
                "version": "3.1"
              },
              "exploitabilityScore": 2.8,
              "impactScore": 3.6,
              "source": "nvd@nist.gov",
              "type": "Primary"
            }
          ]
        },
        "published": "2022-06-18T16:15:08.173",
        "references": [
          {
            "source": "cve@mitre.org",
            "tags": [
              "Third Party Advisory",
              "VDB Entry"
            ],
            "url": "https://exchange.xforce.ibmcloud.com/vulnerabilities/221507"
          },
          {
            "source": "cve@mitre.org",
            "tags": [
              "Third Party Advisory"
            ],
            "url": "https://github.com/python-ldap/python-ldap/security/advisories/GHSA-r8wq-qrxc-hmcm"
          },
          {
            "source": "af854a3a-2127-422b-91ae-364da2661108",
            "tags": [
              "Third Party Advisory",
              "VDB Entry"
            ],
            "url": "https://exchange.xforce.ibmcloud.com/vulnerabilities/221507"
          },
          {
            "source": "af854a3a-2127-422b-91ae-364da2661108",
            "tags": [
              "Third Party Advisory"
            ],
            "url": "https://github.com/python-ldap/python-ldap/security/advisories/GHSA-r8wq-qrxc-hmcm"
          }
        ],
        "sourceIdentifier": "cve@mitre.org",
        "vulnStatus": "Modified",
        "weaknesses": [
          {
            "description": [
              {
                "lang": "en",
                "value": "CWE-1333"
              }
            ],
            "source": "nvd@nist.gov",
            "type": "Primary"
          }
        ]
      }
    },
    "redhat_vex": {
      "aggregate_severity": "Moderate",
      "current_release_date": "2026-06-28T11:11:11+00:00",
      "cve": "CVE-2021-46823",
      "id": "CVE-2021-46823",
      "initial_release_date": "2021-01-01T00:00:00+00:00",
      "product_status:known_affected": "8",
      "product_status:known_not_affected": "2",
      "source": "Red Hat CSAF VEX",
      "status": "final",
      "title": "python-ldap: Regular expression denial of service in LDAP schema parser",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2021/cve-2021-46823.json",
      "version": "3"
    },
    "suse_vex": {
      "aggregate_severity": "moderate",
      "current_release_date": "2026-08-18T00:27:45Z",
      "cve": "CVE-2021-46823",
      "id": "CVE-2021-46823",
      "initial_release_date": "2023-02-15T03:35:55Z",
      "product_status:known_not_affected": "58",
      "source": "SUSE CSAF VEX",
      "status": "interim",
      "title": "SUSE CVE CVE-2021-46823",
      "url": "https://ftp.suse.com/pub/projects/security/csaf-vex/cve-2021-46823.json",
      "version": "11"
    }
  }
}



Log in or create an account to share your comment.




Tags
Taxonomy of the tags.





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.


Detection rules are retrieved from Rulezet.


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.