ubuntu-cve-2025-65496
Vulnerability from osv_ubuntu
Published
2025-11-24 14:15
Modified
2026-05-20 15:22
Summary
Details

NULL pointer dereference in coap_dtls_generate_cookie() in src/coap_openssl.c in OISM libcoap 4.3.5 allows remote attackers to cause a denial of service via a crafted DTLS handshake that triggers SSL_get_SSL_CTX() to return NULL.

Severity
4.3 (Medium)
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L
N/A (UNKNOWN)
medium
References
To clipboard 

{
  "affected": [
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "libcoap-1-0",
            "binary_version": "4.1.2-1"
          },
          {
            "binary_name": "libcoap-1-0-bin",
            "binary_version": "4.1.2-1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:18.04:LTS",
        "name": "libcoap",
        "purl": "pkg:deb/ubuntu/libcoap@4.1.2-1?arch=source\u0026distro=bionic"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "4.1.2-1"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "libcoap2",
            "binary_version": "4.2.1-1"
          },
          {
            "binary_name": "libcoap2-bin",
            "binary_version": "4.2.1-1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:20.04:LTS",
        "name": "libcoap2",
        "purl": "pkg:deb/ubuntu/libcoap2@4.2.1-1?arch=source\u0026distro=focal"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "4.2.0-2",
        "4.2.1-1"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "libcoap2",
            "binary_version": "4.2.1-1build1"
          },
          {
            "binary_name": "libcoap2-bin",
            "binary_version": "4.2.1-1build1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:22.04:LTS",
        "name": "libcoap2",
        "purl": "pkg:deb/ubuntu/libcoap2@4.2.1-1build1?arch=source\u0026distro=jammy"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "4.2.1-1",
        "4.2.1-1build1"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "libcoap3",
            "binary_version": "4.3.0-2build1"
          },
          {
            "binary_name": "libcoap3-bin",
            "binary_version": "4.3.0-2build1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:22.04:LTS",
        "name": "libcoap3",
        "purl": "pkg:deb/ubuntu/libcoap3@4.3.0-2build1?arch=source\u0026distro=jammy"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "4.3.0-2",
        "4.3.0-2build1"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "libcoap3-bin",
            "binary_version": "4.3.4-1.1build4"
          },
          {
            "binary_name": "libcoap3t64",
            "binary_version": "4.3.4-1.1build4"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:24.04:LTS",
        "name": "libcoap3",
        "purl": "pkg:deb/ubuntu/libcoap3@4.3.4-1.1build4?arch=source\u0026distro=noble"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "4.3.1-2",
        "4.3.3-1",
        "4.3.4-1",
        "4.3.4-1.1build2",
        "4.3.4-1.1build3",
        "4.3.4-1.1build4"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "libcoap3-bin",
            "binary_version": "4.3.4-1.1build4"
          },
          {
            "binary_name": "libcoap3t64",
            "binary_version": "4.3.4-1.1build4"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:25.10",
        "name": "libcoap3",
        "purl": "pkg:deb/ubuntu/libcoap3@4.3.4-1.1build4?arch=source\u0026distro=questing"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "4.3.4-1.1build4"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "libcoap3-bin",
            "binary_version": "4.3.5-2"
          },
          {
            "binary_name": "libcoap3t64",
            "binary_version": "4.3.5-2"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:26.04:LTS",
        "name": "libcoap3",
        "purl": "pkg:deb/ubuntu/libcoap3@4.3.5-2?arch=source\u0026distro=resolute"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "4.3.4-1.1build4",
        "4.3.5-1",
        "4.3.5-2"
      ]
    }
  ],
  "aliases": [],
  "details": "NULL pointer dereference in coap_dtls_generate_cookie() in src/coap_openssl.c in OISM libcoap 4.3.5 allows remote attackers to cause a denial of service via a crafted DTLS handshake that triggers SSL_get_SSL_CTX() to return NULL.",
  "id": "UBUNTU-CVE-2025-65496",
  "modified": "2026-05-20T15:22:58Z",
  "published": "2025-11-24T14:15:00Z",
  "references": [
    {
      "type": "REPORT",
      "url": "https://ubuntu.com/security/CVE-2025-65496"
    },
    {
      "type": "REPORT",
      "url": "https://www.cve.org/CVERecord?id=CVE-2025-65496"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/obgm/libcoap/issues/1745"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/obgm/libcoap/pull/1750"
    }
  ],
  "related": [],
  "schema_version": "1.7.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L",
      "type": "CVSS_V3"
    },
    {
      "score": "medium",
      "type": "Ubuntu"
    }
  ],
  "upstream": [
    "CVE-2025-65496"
  ]
}



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