usn-5200-1
Vulnerability from osv_ubuntu
Published
2021-12-17 14:59
Modified
2026-04-22 07:37
Summary
python3.7, python3.8 vulnerabilities
Details

It was discovered that the urllib.request.AbstractBasicAuthHandler class in Python contains regex allowing for catastrophic backtracking. Specially crafted traffic from a malicious HTTP server could cause a regular expression denial of service (ReDoS) condition for a client. (CVE-2020-8492)

It was discovered that the urllib.request.AbstractBasicAuthHandler class in Python contains regex with a quadratic worst-case time complexity. Specially crafted traffic from a malicious HTTP server could cause a regular expression denial of service (ReDoS) condition for a client. (CVE-2021-3733)

It was discovered that the Python urllib http client could enter into an infinite loop when incorrectly handling certain server responses (100 Continue response). Specially crafted traffic from a malicious HTTP server could cause a denial of service (DoS) condition for a client. (CVE-2021-3737)

References
To clipboard 

{
  "affected": [
    {
      "database_specific": {
        "cves_map": {
          "cves": [
            {
              "id": "CVE-2020-8492",
              "severity": [
                {
                  "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H",
                  "type": "CVSS_V3"
                },
                {
                  "score": "low",
                  "type": "Ubuntu"
                }
              ]
            },
            {
              "id": "CVE-2021-3733",
              "severity": [
                {
                  "score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
                  "type": "CVSS_V3"
                },
                {
                  "score": "medium",
                  "type": "Ubuntu"
                }
              ]
            },
            {
              "id": "CVE-2021-3737",
              "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": "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:18.04:LTS"
        }
      },
      "ecosystem_specific": {
        "availability": "No subscription required",
        "binaries": [
          {
            "binary_name": "idle-python3.7",
            "binary_version": "3.7.5-2ubuntu1~18.04.2"
          },
          {
            "binary_name": "libpython3.7",
            "binary_version": "3.7.5-2ubuntu1~18.04.2"
          },
          {
            "binary_name": "libpython3.7-minimal",
            "binary_version": "3.7.5-2ubuntu1~18.04.2"
          },
          {
            "binary_name": "libpython3.7-stdlib",
            "binary_version": "3.7.5-2ubuntu1~18.04.2"
          },
          {
            "binary_name": "libpython3.7-testsuite",
            "binary_version": "3.7.5-2ubuntu1~18.04.2"
          },
          {
            "binary_name": "python3.7",
            "binary_version": "3.7.5-2ubuntu1~18.04.2"
          },
          {
            "binary_name": "python3.7-examples",
            "binary_version": "3.7.5-2ubuntu1~18.04.2"
          },
          {
            "binary_name": "python3.7-minimal",
            "binary_version": "3.7.5-2ubuntu1~18.04.2"
          },
          {
            "binary_name": "python3.7-venv",
            "binary_version": "3.7.5-2ubuntu1~18.04.2"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:18.04:LTS",
        "name": "python3.7",
        "purl": "pkg:deb/ubuntu/python3.7@3.7.5-2ubuntu1~18.04.2?arch=source\u0026distro=bionic"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "3.7.5-2ubuntu1~18.04.2"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "3.7.0~a2-1",
        "3.7.0~a3-1",
        "3.7.0~a3-2",
        "3.7.0~a3-3",
        "3.7.0~a4-1",
        "3.7.0~b1-1",
        "3.7.0~b1-1build1",
        "3.7.0~b2-1",
        "3.7.0~b3-1",
        "3.7.0-1~18.04",
        "3.7.1-1~18.04",
        "3.7.3-2~18.04.1",
        "3.7.5-2~18.04",
        "3.7.5-2~18.04.4"
      ]
    },
    {
      "database_specific": {
        "cves_map": {
          "cves": [
            {
              "id": "CVE-2020-8492",
              "severity": [
                {
                  "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H",
                  "type": "CVSS_V3"
                },
                {
                  "score": "low",
                  "type": "Ubuntu"
                }
              ]
            },
            {
              "id": "CVE-2021-3733",
              "severity": [
                {
                  "score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
                  "type": "CVSS_V3"
                },
                {
                  "score": "medium",
                  "type": "Ubuntu"
                }
              ]
            },
            {
              "id": "CVE-2021-3737",
              "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": "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:18.04:LTS"
        }
      },
      "ecosystem_specific": {
        "availability": "No subscription required",
        "binaries": [
          {
            "binary_name": "idle-python3.8",
            "binary_version": "3.8.0-3ubuntu1~18.04.2"
          },
          {
            "binary_name": "libpython3.8",
            "binary_version": "3.8.0-3ubuntu1~18.04.2"
          },
          {
            "binary_name": "libpython3.8-minimal",
            "binary_version": "3.8.0-3ubuntu1~18.04.2"
          },
          {
            "binary_name": "libpython3.8-stdlib",
            "binary_version": "3.8.0-3ubuntu1~18.04.2"
          },
          {
            "binary_name": "libpython3.8-testsuite",
            "binary_version": "3.8.0-3ubuntu1~18.04.2"
          },
          {
            "binary_name": "python3.8",
            "binary_version": "3.8.0-3ubuntu1~18.04.2"
          },
          {
            "binary_name": "python3.8-examples",
            "binary_version": "3.8.0-3ubuntu1~18.04.2"
          },
          {
            "binary_name": "python3.8-minimal",
            "binary_version": "3.8.0-3ubuntu1~18.04.2"
          },
          {
            "binary_name": "python3.8-venv",
            "binary_version": "3.8.0-3ubuntu1~18.04.2"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:18.04:LTS",
        "name": "python3.8",
        "purl": "pkg:deb/ubuntu/python3.8@3.8.0-3ubuntu1~18.04.2?arch=source\u0026distro=bionic"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "3.8.0-3ubuntu1~18.04.2"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "3.8.0-3~18.04",
        "3.8.0-3~18.04.1"
      ]
    }
  ],
  "aliases": [],
  "details": "\nIt was discovered that the urllib.request.AbstractBasicAuthHandler class \nin Python contains regex allowing for catastrophic backtracking. Specially \ncrafted traffic from a malicious HTTP server could cause a regular expression \ndenial of service (ReDoS) condition for a client.\n(CVE-2020-8492)\n\nIt was discovered that the urllib.request.AbstractBasicAuthHandler class \nin Python contains regex with a quadratic worst-case time complexity. \nSpecially crafted traffic from a malicious HTTP server could cause a regular \nexpression denial of service (ReDoS) condition for a client.\n(CVE-2021-3733)\n\nIt was discovered that the Python urllib http client could enter into an infinite \nloop when incorrectly handling certain server responses (100 Continue response). \nSpecially crafted traffic from a malicious HTTP server could cause a denial of \nservice (DoS) condition for a client.\n(CVE-2021-3737)\n\n",
  "id": "USN-5200-1",
  "modified": "2026-04-22T07:37:00Z",
  "published": "2021-12-17T14:59:29Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://ubuntu.com/security/notices/USN-5200-1"
    },
    {
      "type": "REPORT",
      "url": "https://ubuntu.com/security/CVE-2020-8492"
    },
    {
      "type": "REPORT",
      "url": "https://ubuntu.com/security/CVE-2021-3733"
    },
    {
      "type": "REPORT",
      "url": "https://ubuntu.com/security/CVE-2021-3737"
    }
  ],
  "related": [],
  "schema_version": "1.7.0",
  "summary": "python3.7, python3.8 vulnerabilities",
  "upstream": [
    "UBUNTU-CVE-2020-8492",
    "UBUNTU-CVE-2021-3733",
    "UBUNTU-CVE-2021-3737"
  ]
}



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