Vulnerability-Lookup

FKIE_CVE-2019-19521

Vulnerability from fkie_nvd - Published: 2019-12-05 00:15 - Updated: 2026-06-17 02:26

Severity

9.8 (Critical) - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Summary

libc in OpenBSD 6.6 allows authentication bypass via the -schallenge username, as demonstrated by smtpd, ldapd, or radiusd. This is related to gen/auth_subr.c and gen/authenticate.c in libc (and login/login.c and xenocara/app/xenodm/greeter/verify.c).

References

URL	Tags
cve@mitre.org	http://packetstormsecurity.com/files/155572/Qualys-Security-Advisory-OpenBSD-Authentication-Bypass-Privilege-Escalation.html	Third Party Advisory
cve@mitre.org	http://seclists.org/fulldisclosure/2019/Dec/14	Third Party Advisory
cve@mitre.org	http://www.openwall.com/lists/oss-security/2019/12/04/5	Exploit, Mailing List, Third Party Advisory
cve@mitre.org	http://www.openwall.com/lists/oss-security/2019/12/04/6	Mailing List
cve@mitre.org	https://seclists.org/bugtraq/2019/Dec/8	Exploit, Mailing List, Third Party Advisory
cve@mitre.org	https://www.openbsd.org/errata66.html	Vendor Advisory
cve@mitre.org	https://www.openwall.com/lists/oss-security/2019/12/04/5	Exploit, Mailing List, Third Party Advisory
af854a3a-2127-422b-91ae-364da2661108	http://packetstormsecurity.com/files/155572/Qualys-Security-Advisory-OpenBSD-Authentication-Bypass-Privilege-Escalation.html	Third Party Advisory
af854a3a-2127-422b-91ae-364da2661108	http://seclists.org/fulldisclosure/2019/Dec/14	Third Party Advisory
af854a3a-2127-422b-91ae-364da2661108	http://www.openwall.com/lists/oss-security/2019/12/04/5	Exploit, Mailing List, Third Party Advisory
af854a3a-2127-422b-91ae-364da2661108	http://www.openwall.com/lists/oss-security/2019/12/04/6	Mailing List
af854a3a-2127-422b-91ae-364da2661108	https://seclists.org/bugtraq/2019/Dec/8	Exploit, Mailing List, Third Party Advisory
af854a3a-2127-422b-91ae-364da2661108	https://www.openbsd.org/errata66.html	Vendor Advisory
af854a3a-2127-422b-91ae-364da2661108	https://www.openwall.com/lists/oss-security/2019/12/04/5	Exploit, Mailing List, Third Party Advisory

Impacted products

	Vendor	Product	Version
	openbsd	openbsd	6.6

JSON

To clipboard

{
  "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:o:openbsd:openbsd:6.6:*:*:*:*:*:*:*",
              "matchCriteriaId": "0E0CC007-1428-4683-A196-3544F1C9CC92",
              "vulnerable": true
            }
          ],
          "negate": false,
          "operator": "OR"
        }
      ]
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "libc in OpenBSD 6.6 allows authentication bypass via the -schallenge username, as demonstrated by smtpd, ldapd, or radiusd. This is related to gen/auth_subr.c and gen/authenticate.c in libc (and login/login.c and xenocara/app/xenodm/greeter/verify.c)."
    },
    {
      "lang": "es",
      "value": "libc en OpenBSD versi\u00f3n 6.6, permite omitir la autenticaci\u00f3n por medio del nombre de usuario -schallenge, como es demostrado por smtpd, ldapd o radiusd. Esto est\u00e1 relacionado con los archivos gen/auth_subr.c y gen/authenticate.c en libc (y los archivos login/login.c y xenocara/app/xenodm/greeter/verify.c)."
    }
  ],
  "id": "CVE-2019-19521",
  "lastModified": "2026-06-17T02:26:48.050",
  "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": "2019-12-05T00:15:11.400",
  "references": [
    {
      "source": "cve@mitre.org",
      "tags": [
        "Third Party Advisory"
      ],
      "url": "http://packetstormsecurity.com/files/155572/Qualys-Security-Advisory-OpenBSD-Authentication-Bypass-Privilege-Escalation.html"
    },
    {
      "source": "cve@mitre.org",
      "tags": [
        "Third Party Advisory"
      ],
      "url": "http://seclists.org/fulldisclosure/2019/Dec/14"
    },
    {
      "source": "cve@mitre.org",
      "tags": [
        "Exploit",
        "Mailing List",
        "Third Party Advisory"
      ],
      "url": "http://www.openwall.com/lists/oss-security/2019/12/04/5"
    },
    {
      "source": "cve@mitre.org",
      "tags": [
        "Mailing List"
      ],
      "url": "http://www.openwall.com/lists/oss-security/2019/12/04/6"
    },
    {
      "source": "cve@mitre.org",
      "tags": [
        "Exploit",
        "Mailing List",
        "Third Party Advisory"
      ],
      "url": "https://seclists.org/bugtraq/2019/Dec/8"
    },
    {
      "source": "cve@mitre.org",
      "tags": [
        "Vendor Advisory"
      ],
      "url": "https://www.openbsd.org/errata66.html"
    },
    {
      "source": "cve@mitre.org",
      "tags": [
        "Exploit",
        "Mailing List",
        "Third Party Advisory"
      ],
      "url": "https://www.openwall.com/lists/oss-security/2019/12/04/5"
    },
    {
      "source": "af854a3a-2127-422b-91ae-364da2661108",
      "tags": [
        "Third Party Advisory"
      ],
      "url": "http://packetstormsecurity.com/files/155572/Qualys-Security-Advisory-OpenBSD-Authentication-Bypass-Privilege-Escalation.html"
    },
    {
      "source": "af854a3a-2127-422b-91ae-364da2661108",
      "tags": [
        "Third Party Advisory"
      ],
      "url": "http://seclists.org/fulldisclosure/2019/Dec/14"
    },
    {
      "source": "af854a3a-2127-422b-91ae-364da2661108",
      "tags": [
        "Exploit",
        "Mailing List",
        "Third Party Advisory"
      ],
      "url": "http://www.openwall.com/lists/oss-security/2019/12/04/5"
    },
    {
      "source": "af854a3a-2127-422b-91ae-364da2661108",
      "tags": [
        "Mailing List"
      ],
      "url": "http://www.openwall.com/lists/oss-security/2019/12/04/6"
    },
    {
      "source": "af854a3a-2127-422b-91ae-364da2661108",
      "tags": [
        "Exploit",
        "Mailing List",
        "Third Party Advisory"
      ],
      "url": "https://seclists.org/bugtraq/2019/Dec/8"
    },
    {
      "source": "af854a3a-2127-422b-91ae-364da2661108",
      "tags": [
        "Vendor Advisory"
      ],
      "url": "https://www.openbsd.org/errata66.html"
    },
    {
      "source": "af854a3a-2127-422b-91ae-364da2661108",
      "tags": [
        "Exploit",
        "Mailing List",
        "Third Party Advisory"
      ],
      "url": "https://www.openwall.com/lists/oss-security/2019/12/04/5"
    }
  ],
  "sourceIdentifier": "cve@mitre.org",
  "vulnStatus": "Modified",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-287"
        }
      ],
      "source": "nvd@nist.gov",
      "type": "Primary"
    }
  ]
}

CVE-2019-19521 (GCVE-0-2019-19521)

Vulnerability from cvelistv5 – Published: 2019-12-04 23:33 – Updated: 2024-08-05 02:16

Summary

Severity

No CVSS data available.

CWE

Assigner

mitre mitre root

References

7 references

URL	Tags
https://www.openwall.com/lists/oss-security/2019/…	x_refsource_MISC
https://www.openbsd.org/errata66.html	x_refsource_MISC
http://www.openwall.com/lists/oss-security/2019/12/04/6	mailing-listx_refsource_MLIST
http://www.openwall.com/lists/oss-security/2019/12/04/5	mailing-listx_refsource_MLIST
https://seclists.org/bugtraq/2019/Dec/8	mailing-listx_refsource_BUGTRAQ
http://packetstormsecurity.com/files/155572/Qualy…	x_refsource_MISC
http://seclists.org/fulldisclosure/2019/Dec/14	mailing-listx_refsource_FULLDISC

Show details on NVD website

JSON

To clipboard

{
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        "providerMetadata": {
          "dateUpdated": "2024-08-05T02:16:47.981Z",
          "orgId": "af854a3a-2127-422b-91ae-364da2661108",
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              "x_refsource_MISC",
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            ],
            "url": "https://www.openbsd.org/errata66.html"
          },
          {
            "name": "[oss-security] 20191204 Re: Authentication vulnerabilities in OpenBSD",
            "tags": [
              "mailing-list",
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            ],
            "url": "http://www.openwall.com/lists/oss-security/2019/12/04/6"
          },
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            "url": "http://packetstormsecurity.com/files/155572/Qualys-Security-Advisory-OpenBSD-Authentication-Bypass-Privilege-Escalation.html"
          },
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            "name": "20191206 Authentication vulnerabilities in OpenBSD",
            "tags": [
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              "x_transferred"
            ],
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          }
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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.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.

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.

Action not permitted

FKIE_CVE-2019-19521

CVE-2019-19521 (GCVE-0-2019-19521)

Tags

Sightings

Nomenclature

Related by attack behaviour