ubuntu-cve-2023-27535
Vulnerability from osv_ubuntu
Published
2023-03-20 00:00
Modified
2026-04-22 07:45
Summary
Details

An authentication bypass vulnerability exists in libcurl <8.0.0 in the FTP connection reuse feature that can result in wrong credentials being used during subsequent transfers. Previously created connections are kept in a connection pool for reuse if they match the current setup. However, certain FTP settings such as CURLOPT_FTP_ACCOUNT, CURLOPT_FTP_ALTERNATIVE_TO_USER, CURLOPT_FTP_SSL_CCC, and CURLOPT_USE_SSL were not included in the configuration match checks, causing them to match too easily. This could lead to libcurl using the wrong credentials when performing a transfer, potentially allowing unauthorized access to sensitive information.

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

{
  "affected": [
    {
      "ecosystem_specific": {
        "availability": "Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro",
        "binaries": [
          {
            "binary_name": "curl",
            "binary_version": "7.35.0-1ubuntu2.20+esm15"
          },
          {
            "binary_name": "libcurl3",
            "binary_version": "7.35.0-1ubuntu2.20+esm15"
          },
          {
            "binary_name": "libcurl3-gnutls",
            "binary_version": "7.35.0-1ubuntu2.20+esm15"
          },
          {
            "binary_name": "libcurl3-nss",
            "binary_version": "7.35.0-1ubuntu2.20+esm15"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:Pro:14.04:LTS",
        "name": "curl",
        "purl": "pkg:deb/ubuntu/curl@7.35.0-1ubuntu2.20+esm15?arch=source\u0026distro=trusty/esm"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "7.35.0-1ubuntu2.20+esm15"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "7.32.0-1ubuntu1",
        "7.33.0-1ubuntu1",
        "7.34.0-1ubuntu1",
        "7.35.0-1ubuntu1",
        "7.35.0-1ubuntu2",
        "7.35.0-1ubuntu2.1",
        "7.35.0-1ubuntu2.2",
        "7.35.0-1ubuntu2.3",
        "7.35.0-1ubuntu2.5",
        "7.35.0-1ubuntu2.6",
        "7.35.0-1ubuntu2.7",
        "7.35.0-1ubuntu2.8",
        "7.35.0-1ubuntu2.9",
        "7.35.0-1ubuntu2.10",
        "7.35.0-1ubuntu2.11",
        "7.35.0-1ubuntu2.12",
        "7.35.0-1ubuntu2.13",
        "7.35.0-1ubuntu2.14",
        "7.35.0-1ubuntu2.15",
        "7.35.0-1ubuntu2.16",
        "7.35.0-1ubuntu2.17",
        "7.35.0-1ubuntu2.19",
        "7.35.0-1ubuntu2.20",
        "7.35.0-1ubuntu2.20+esm2",
        "7.35.0-1ubuntu2.20+esm3",
        "7.35.0-1ubuntu2.20+esm4",
        "7.35.0-1ubuntu2.20+esm5",
        "7.35.0-1ubuntu2.20+esm6",
        "7.35.0-1ubuntu2.20+esm7",
        "7.35.0-1ubuntu2.20+esm8",
        "7.35.0-1ubuntu2.20+esm9",
        "7.35.0-1ubuntu2.20+esm10",
        "7.35.0-1ubuntu2.20+esm11",
        "7.35.0-1ubuntu2.20+esm12",
        "7.35.0-1ubuntu2.20+esm13",
        "7.35.0-1ubuntu2.20+esm14"
      ]
    },
    {
      "ecosystem_specific": {
        "availability": "Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro",
        "binaries": [
          {
            "binary_name": "curl",
            "binary_version": "7.47.0-1ubuntu2.19+esm8"
          },
          {
            "binary_name": "libcurl3",
            "binary_version": "7.47.0-1ubuntu2.19+esm8"
          },
          {
            "binary_name": "libcurl3-gnutls",
            "binary_version": "7.47.0-1ubuntu2.19+esm8"
          },
          {
            "binary_name": "libcurl3-nss",
            "binary_version": "7.47.0-1ubuntu2.19+esm8"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:Pro:16.04:LTS",
        "name": "curl",
        "purl": "pkg:deb/ubuntu/curl@7.47.0-1ubuntu2.19+esm8?arch=source\u0026distro=esm-infra/xenial"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "7.47.0-1ubuntu2.19+esm8"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "7.43.0-1ubuntu2",
        "7.45.0-1ubuntu1",
        "7.46.0-1ubuntu1",
        "7.47.0-1ubuntu1",
        "7.47.0-1ubuntu2",
        "7.47.0-1ubuntu2.1",
        "7.47.0-1ubuntu2.2",
        "7.47.0-1ubuntu2.3",
        "7.47.0-1ubuntu2.4",
        "7.47.0-1ubuntu2.5",
        "7.47.0-1ubuntu2.6",
        "7.47.0-1ubuntu2.7",
        "7.47.0-1ubuntu2.8",
        "7.47.0-1ubuntu2.9",
        "7.47.0-1ubuntu2.11",
        "7.47.0-1ubuntu2.12",
        "7.47.0-1ubuntu2.13",
        "7.47.0-1ubuntu2.14",
        "7.47.0-1ubuntu2.15",
        "7.47.0-1ubuntu2.16",
        "7.47.0-1ubuntu2.18",
        "7.47.0-1ubuntu2.19",
        "7.47.0-1ubuntu2.19+esm1",
        "7.47.0-1ubuntu2.19+esm2",
        "7.47.0-1ubuntu2.19+esm3",
        "7.47.0-1ubuntu2.19+esm4",
        "7.47.0-1ubuntu2.19+esm5",
        "7.47.0-1ubuntu2.19+esm6",
        "7.47.0-1ubuntu2.19+esm7"
      ]
    },
    {
      "ecosystem_specific": {
        "availability": "No subscription required",
        "binaries": [
          {
            "binary_name": "curl",
            "binary_version": "7.58.0-2ubuntu3.24"
          },
          {
            "binary_name": "libcurl3-gnutls",
            "binary_version": "7.58.0-2ubuntu3.24"
          },
          {
            "binary_name": "libcurl3-nss",
            "binary_version": "7.58.0-2ubuntu3.24"
          },
          {
            "binary_name": "libcurl4",
            "binary_version": "7.58.0-2ubuntu3.24"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:18.04:LTS",
        "name": "curl",
        "purl": "pkg:deb/ubuntu/curl@7.58.0-2ubuntu3.24?arch=source\u0026distro=bionic"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "7.58.0-2ubuntu3.24"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "7.55.1-1ubuntu2",
        "7.55.1-1ubuntu2.1",
        "7.57.0-1ubuntu1",
        "7.58.0-2ubuntu1",
        "7.58.0-2ubuntu2",
        "7.58.0-2ubuntu3",
        "7.58.0-2ubuntu3.1",
        "7.58.0-2ubuntu3.2",
        "7.58.0-2ubuntu3.3",
        "7.58.0-2ubuntu3.5",
        "7.58.0-2ubuntu3.6",
        "7.58.0-2ubuntu3.7",
        "7.58.0-2ubuntu3.8",
        "7.58.0-2ubuntu3.9",
        "7.58.0-2ubuntu3.10",
        "7.58.0-2ubuntu3.12",
        "7.58.0-2ubuntu3.13",
        "7.58.0-2ubuntu3.14",
        "7.58.0-2ubuntu3.15",
        "7.58.0-2ubuntu3.16",
        "7.58.0-2ubuntu3.17",
        "7.58.0-2ubuntu3.18",
        "7.58.0-2ubuntu3.19",
        "7.58.0-2ubuntu3.20",
        "7.58.0-2ubuntu3.21",
        "7.58.0-2ubuntu3.22",
        "7.58.0-2ubuntu3.23"
      ]
    },
    {
      "ecosystem_specific": {
        "availability": "No subscription required",
        "binaries": [
          {
            "binary_name": "curl",
            "binary_version": "7.68.0-1ubuntu2.18"
          },
          {
            "binary_name": "libcurl3-gnutls",
            "binary_version": "7.68.0-1ubuntu2.18"
          },
          {
            "binary_name": "libcurl3-nss",
            "binary_version": "7.68.0-1ubuntu2.18"
          },
          {
            "binary_name": "libcurl4",
            "binary_version": "7.68.0-1ubuntu2.18"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:20.04:LTS",
        "name": "curl",
        "purl": "pkg:deb/ubuntu/curl@7.68.0-1ubuntu2.18?arch=source\u0026distro=focal"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "7.68.0-1ubuntu2.18"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "7.65.3-1ubuntu3",
        "7.65.3-1ubuntu4",
        "7.66.0-1ubuntu1",
        "7.67.0-2ubuntu1",
        "7.68.0-1ubuntu1",
        "7.68.0-1ubuntu2",
        "7.68.0-1ubuntu2.1",
        "7.68.0-1ubuntu2.2",
        "7.68.0-1ubuntu2.4",
        "7.68.0-1ubuntu2.5",
        "7.68.0-1ubuntu2.6",
        "7.68.0-1ubuntu2.7",
        "7.68.0-1ubuntu2.10",
        "7.68.0-1ubuntu2.11",
        "7.68.0-1ubuntu2.12",
        "7.68.0-1ubuntu2.13",
        "7.68.0-1ubuntu2.14",
        "7.68.0-1ubuntu2.15",
        "7.68.0-1ubuntu2.16"
      ]
    },
    {
      "ecosystem_specific": {
        "availability": "No subscription required",
        "binaries": [
          {
            "binary_name": "curl",
            "binary_version": "7.81.0-1ubuntu1.10"
          },
          {
            "binary_name": "libcurl3-gnutls",
            "binary_version": "7.81.0-1ubuntu1.10"
          },
          {
            "binary_name": "libcurl3-nss",
            "binary_version": "7.81.0-1ubuntu1.10"
          },
          {
            "binary_name": "libcurl4",
            "binary_version": "7.81.0-1ubuntu1.10"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:22.04:LTS",
        "name": "curl",
        "purl": "pkg:deb/ubuntu/curl@7.81.0-1ubuntu1.10?arch=source\u0026distro=jammy"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "7.81.0-1ubuntu1.10"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "7.74.0-1.3ubuntu2",
        "7.74.0-1.3ubuntu3",
        "7.80.0-3",
        "7.81.0-1",
        "7.81.0-1ubuntu1.1",
        "7.81.0-1ubuntu1.2",
        "7.81.0-1ubuntu1.3",
        "7.81.0-1ubuntu1.4",
        "7.81.0-1ubuntu1.6",
        "7.81.0-1ubuntu1.7",
        "7.81.0-1ubuntu1.8"
      ]
    }
  ],
  "aliases": [],
  "details": "An authentication bypass vulnerability exists in libcurl \u003c8.0.0 in the FTP connection reuse feature that can result in wrong credentials being used during subsequent transfers. Previously created connections are kept in a connection pool for reuse if they match the current setup. However, certain FTP settings such as CURLOPT_FTP_ACCOUNT, CURLOPT_FTP_ALTERNATIVE_TO_USER, CURLOPT_FTP_SSL_CCC, and CURLOPT_USE_SSL were not included in the configuration match checks, causing them to match too easily. This could lead to libcurl using the wrong credentials when performing a transfer, potentially allowing unauthorized access to sensitive information.",
  "id": "UBUNTU-CVE-2023-27535",
  "modified": "2026-04-22T07:45:16Z",
  "published": "2023-03-20T00:00:00Z",
  "references": [
    {
      "type": "REPORT",
      "url": "https://ubuntu.com/security/CVE-2023-27535"
    },
    {
      "type": "REPORT",
      "url": "https://curl.se/docs/CVE-2023-27535.html"
    },
    {
      "type": "ADVISORY",
      "url": "https://ubuntu.com/security/notices/USN-5964-1"
    },
    {
      "type": "ADVISORY",
      "url": "https://ubuntu.com/security/notices/USN-5964-2"
    },
    {
      "type": "REPORT",
      "url": "https://www.cve.org/CVERecord?id=CVE-2023-27535"
    }
  ],
  "related": [
    "USN-5964-1",
    "USN-5964-2"
  ],
  "schema_version": "1.7.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N",
      "type": "CVSS_V3"
    },
    {
      "score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N",
      "type": "CVSS_V3"
    },
    {
      "score": "medium",
      "type": "Ubuntu"
    }
  ],
  "upstream": [
    "CVE-2023-27535"
  ]
}



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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.