Vulnerability-Lookup

USN-4491-1 (UBUNTU-CVE-2020-24659)

Vulnerability from osv_ubuntu – Published: 2020-09-09 11:04 – Updated: 2026-04-22 07:36 – Source website

Summary

gnutls28 vulnerability

Details

It was discovered that GnuTLS incorrectly handled certain alerts when being used with TLS 1.3 servers. A remote attacker could use this issue to cause GnuTLS to crash, resulting in a denial of service, or possibly execute arbitrary code.

References

URL

Type

	https://ubuntu.com/security/notices/USN-4491-1	ADVISORY
	https://ubuntu.com/security/CVE-2020-24659	REPORT

JSON

To clipboard

{
  "affected": [
    {
      "database_specific": {
        "cves_map": {
          "cves": [
            {
              "id": "CVE-2020-24659",
              "severity": [
                {
                  "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
                  "type": "CVSS_V3"
                },
                {
                  "score": "medium",
                  "type": "Ubuntu"
                }
              ]
            }
          ],
          "ecosystem": "Ubuntu:20.04:LTS"
        }
      },
      "ecosystem_specific": {
        "availability": "No subscription required",
        "binaries": [
          {
            "binary_name": "gnutls-bin",
            "binary_version": "3.6.13-2ubuntu1.3"
          },
          {
            "binary_name": "guile-gnutls",
            "binary_version": "3.6.13-2ubuntu1.3"
          },
          {
            "binary_name": "libgnutls-dane0",
            "binary_version": "3.6.13-2ubuntu1.3"
          },
          {
            "binary_name": "libgnutls-openssl27",
            "binary_version": "3.6.13-2ubuntu1.3"
          },
          {
            "binary_name": "libgnutls30",
            "binary_version": "3.6.13-2ubuntu1.3"
          },
          {
            "binary_name": "libgnutlsxx28",
            "binary_version": "3.6.13-2ubuntu1.3"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:20.04:LTS",
        "name": "gnutls28",
        "purl": "pkg:deb/ubuntu/gnutls28@3.6.13-2ubuntu1.3?arch=source\u0026distro=focal"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "3.6.13-2ubuntu1.3"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "3.6.9-5ubuntu1",
        "3.6.9-5ubuntu2",
        "3.6.10-5",
        "3.6.11.1-2",
        "3.6.11.1-2ubuntu2",
        "3.6.13-2ubuntu1",
        "3.6.13-2ubuntu1.1",
        "3.6.13-2ubuntu1.2"
      ]
    }
  ],
  "aliases": [],
  "details": "It was discovered that GnuTLS incorrectly handled certain alerts when being\nused with TLS 1.3 servers. A remote attacker could use this issue to cause\nGnuTLS to crash, resulting in a denial of service, or possibly execute\narbitrary code.\n",
  "id": "USN-4491-1",
  "modified": "2026-04-22T07:36:39Z",
  "published": "2020-09-09T11:04:03Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://ubuntu.com/security/notices/USN-4491-1"
    },
    {
      "type": "REPORT",
      "url": "https://ubuntu.com/security/CVE-2020-24659"
    }
  ],
  "related": [],
  "schema_version": "1.7.0",
  "summary": "gnutls28 vulnerability",
  "upstream": [
    "UBUNTU-CVE-2020-24659"
  ]
}

UBUNTU-CVE-2020-24659 (CVE-2020-24659)

Vulnerability from osv_ubuntu – Published: 2020-09-04 15:15 – Updated: 2026-04-22 07:39 – Source website

Details

An issue was discovered in GnuTLS before 3.6.15. A server can trigger a NULL pointer dereference in a TLS 1.3 client if a no_renegotiation alert is sent with unexpected timing, and then an invalid second handshake occurs. The crash happens in the application's error handling path, where the gnutls_deinit function is called after detecting a handshake failure.

Severity

7.5 (High)


                    
                      CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

N/A (UNKNOWN)


                    
                      medium

References

URL

Type

	https://ubuntu.com/security/CVE-2020-24659	REPORT
	https://www.gnutls.org/security-new.html#GNUTLS-S…	REPORT
	https://security.gentoo.org/glsa/202009-01	REPORT
	https://ubuntu.com/security/notices/USN-4491-1	ADVISORY
	https://www.cve.org/CVERecord?id=CVE-2020-24659	REPORT

JSON

To clipboard

{
  "affected": [
    {
      "ecosystem_specific": {
        "availability": "No subscription required",
        "binaries": [
          {
            "binary_name": "gnutls-bin",
            "binary_version": "3.6.13-2ubuntu1.3"
          },
          {
            "binary_name": "guile-gnutls",
            "binary_version": "3.6.13-2ubuntu1.3"
          },
          {
            "binary_name": "libgnutls-dane0",
            "binary_version": "3.6.13-2ubuntu1.3"
          },
          {
            "binary_name": "libgnutls-openssl27",
            "binary_version": "3.6.13-2ubuntu1.3"
          },
          {
            "binary_name": "libgnutls30",
            "binary_version": "3.6.13-2ubuntu1.3"
          },
          {
            "binary_name": "libgnutlsxx28",
            "binary_version": "3.6.13-2ubuntu1.3"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:20.04:LTS",
        "name": "gnutls28",
        "purl": "pkg:deb/ubuntu/gnutls28@3.6.13-2ubuntu1.3?arch=source\u0026distro=focal"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "3.6.13-2ubuntu1.3"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "3.6.9-5ubuntu1",
        "3.6.9-5ubuntu2",
        "3.6.10-5",
        "3.6.11.1-2",
        "3.6.11.1-2ubuntu2",
        "3.6.13-2ubuntu1",
        "3.6.13-2ubuntu1.1",
        "3.6.13-2ubuntu1.2"
      ]
    }
  ],
  "aliases": [],
  "details": "An issue was discovered in GnuTLS before 3.6.15. A server can trigger a NULL pointer dereference in a TLS 1.3 client if a no_renegotiation alert is sent with unexpected timing, and then an invalid second handshake occurs. The crash happens in the application\u0027s error handling path, where the gnutls_deinit function is called after detecting a handshake failure.",
  "id": "UBUNTU-CVE-2020-24659",
  "modified": "2026-04-22T07:39:31Z",
  "published": "2020-09-04T15:15:00Z",
  "references": [
    {
      "type": "REPORT",
      "url": "https://ubuntu.com/security/CVE-2020-24659"
    },
    {
      "type": "REPORT",
      "url": "https://www.gnutls.org/security-new.html#GNUTLS-SA-2020-09-04"
    },
    {
      "type": "REPORT",
      "url": "https://security.gentoo.org/glsa/202009-01"
    },
    {
      "type": "ADVISORY",
      "url": "https://ubuntu.com/security/notices/USN-4491-1"
    },
    {
      "type": "REPORT",
      "url": "https://www.cve.org/CVERecord?id=CVE-2020-24659"
    }
  ],
  "related": [
    "USN-4491-1"
  ],
  "schema_version": "1.7.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
      "type": "CVSS_V3"
    },
    {
      "score": "medium",
      "type": "Ubuntu"
    }
  ],
  "upstream": [
    "CVE-2020-24659"
  ]
}

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.