Vulnerability-Lookup

UBUNTU-CVE-2021-33620 (CVE-2021-33620)

Vulnerability from osv_ubuntu – Published: 2021-05-28 12:15 – Updated: 2025-11-05 04:50 – Source website

Details

Squid before 4.15 and 5.x before 5.0.6 allows remote servers to cause a denial of service (affecting availability to all clients) via an HTTP response. The issue trigger is a header that can be expected to exist in HTTP traffic without any malicious intent by the server.

Severity

6.5 (Medium)


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

6.5 (Medium)


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

N/A (UNKNOWN)


                    
                      medium

References

URL

Type

	https://ubuntu.com/security/CVE-2021-33620	REPORT
	https://github.com/squid-cache/squid/security/adv…	REPORT
	https://ubuntu.com/security/notices/USN-4981-1	ADVISORY
	https://www.cve.org/CVERecord?id=CVE-2021-33620	REPORT

JSON

To clipboard

{
  "affected": [
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "squid",
            "binary_version": "3.5.12-1ubuntu7.16+esm6"
          },
          {
            "binary_name": "squid-cgi",
            "binary_version": "3.5.12-1ubuntu7.16+esm6"
          },
          {
            "binary_name": "squid-common",
            "binary_version": "3.5.12-1ubuntu7.16+esm6"
          },
          {
            "binary_name": "squid-purge",
            "binary_version": "3.5.12-1ubuntu7.16+esm6"
          },
          {
            "binary_name": "squid3",
            "binary_version": "3.5.12-1ubuntu7.16+esm6"
          },
          {
            "binary_name": "squidclient",
            "binary_version": "3.5.12-1ubuntu7.16+esm6"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:Pro:16.04:LTS",
        "name": "squid3",
        "purl": "pkg:deb/ubuntu/squid3@3.5.12-1ubuntu7.16+esm6?arch=source\u0026distro=esm-infra/xenial"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "3.3.8-1ubuntu16",
        "3.3.8-1ubuntu17",
        "3.5.12-1ubuntu6",
        "3.5.12-1ubuntu7",
        "3.5.12-1ubuntu7.1",
        "3.5.12-1ubuntu7.2",
        "3.5.12-1ubuntu7.3",
        "3.5.12-1ubuntu7.4",
        "3.5.12-1ubuntu7.5",
        "3.5.12-1ubuntu7.6",
        "3.5.12-1ubuntu7.7",
        "3.5.12-1ubuntu7.8",
        "3.5.12-1ubuntu7.9",
        "3.5.12-1ubuntu7.10",
        "3.5.12-1ubuntu7.11",
        "3.5.12-1ubuntu7.12",
        "3.5.12-1ubuntu7.13",
        "3.5.12-1ubuntu7.14",
        "3.5.12-1ubuntu7.15",
        "3.5.12-1ubuntu7.16",
        "3.5.12-1ubuntu7.16+esm1",
        "3.5.12-1ubuntu7.16+esm2",
        "3.5.12-1ubuntu7.16+esm3",
        "3.5.12-1ubuntu7.16+esm4",
        "3.5.12-1ubuntu7.16+esm5",
        "3.5.12-1ubuntu7.16+esm6"
      ]
    },
    {
      "ecosystem_specific": {
        "availability": "No subscription required",
        "binaries": [
          {
            "binary_name": "squid",
            "binary_version": "3.5.27-1ubuntu1.11"
          },
          {
            "binary_name": "squid-cgi",
            "binary_version": "3.5.27-1ubuntu1.11"
          },
          {
            "binary_name": "squid-common",
            "binary_version": "3.5.27-1ubuntu1.11"
          },
          {
            "binary_name": "squid-purge",
            "binary_version": "3.5.27-1ubuntu1.11"
          },
          {
            "binary_name": "squid3",
            "binary_version": "3.5.27-1ubuntu1.11"
          },
          {
            "binary_name": "squidclient",
            "binary_version": "3.5.27-1ubuntu1.11"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:18.04:LTS",
        "name": "squid3",
        "purl": "pkg:deb/ubuntu/squid3@3.5.27-1ubuntu1.11?arch=source\u0026distro=bionic"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "3.5.27-1ubuntu1.11"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "3.5.23-5ubuntu1",
        "3.5.23-5ubuntu2",
        "3.5.27-1ubuntu1",
        "3.5.27-1ubuntu1.1",
        "3.5.27-1ubuntu1.2",
        "3.5.27-1ubuntu1.3",
        "3.5.27-1ubuntu1.4",
        "3.5.27-1ubuntu1.5",
        "3.5.27-1ubuntu1.6",
        "3.5.27-1ubuntu1.7",
        "3.5.27-1ubuntu1.8",
        "3.5.27-1ubuntu1.9",
        "3.5.27-1ubuntu1.10"
      ]
    },
    {
      "ecosystem_specific": {
        "availability": "No subscription required",
        "binaries": [
          {
            "binary_name": "squid",
            "binary_version": "4.10-1ubuntu1.4"
          },
          {
            "binary_name": "squid-cgi",
            "binary_version": "4.10-1ubuntu1.4"
          },
          {
            "binary_name": "squid-common",
            "binary_version": "4.10-1ubuntu1.4"
          },
          {
            "binary_name": "squid-purge",
            "binary_version": "4.10-1ubuntu1.4"
          },
          {
            "binary_name": "squidclient",
            "binary_version": "4.10-1ubuntu1.4"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:20.04:LTS",
        "name": "squid",
        "purl": "pkg:deb/ubuntu/squid@4.10-1ubuntu1.4?arch=source\u0026distro=focal"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "4.10-1ubuntu1.4"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "4.8-1ubuntu2",
        "4.8-1ubuntu3",
        "4.9-2ubuntu1",
        "4.9-2ubuntu2",
        "4.9-2ubuntu3",
        "4.9-2ubuntu4",
        "4.10-1ubuntu1",
        "4.10-1ubuntu1.1",
        "4.10-1ubuntu1.2",
        "4.10-1ubuntu1.3"
      ]
    }
  ],
  "aliases": [],
  "details": "Squid before 4.15 and 5.x before 5.0.6 allows remote servers to cause a denial of service (affecting availability to all clients) via an HTTP response. The issue trigger is a header that can be expected to exist in HTTP traffic without any malicious intent by the server.",
  "id": "UBUNTU-CVE-2021-33620",
  "modified": "2025-11-05T04:50:09Z",
  "published": "2021-05-28T12:15:00Z",
  "references": [
    {
      "type": "REPORT",
      "url": "https://ubuntu.com/security/CVE-2021-33620"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/squid-cache/squid/security/advisories/GHSA-572g-rvwr-6c7f"
    },
    {
      "type": "ADVISORY",
      "url": "https://ubuntu.com/security/notices/USN-4981-1"
    },
    {
      "type": "REPORT",
      "url": "https://www.cve.org/CVERecord?id=CVE-2021-33620"
    }
  ],
  "related": [
    "USN-4981-1"
  ],
  "schema_version": "1.7.0",
  "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": "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"
    }
  ],
  "upstream": [
    "CVE-2021-33620"
  ]
}

CVE-2021-33620 (GCVE-0-2021-33620)

Vulnerability from cvelistv5 – Published: 2021-05-28 00:00 – Updated: 2024-08-03 23:58

Summary

Severity

6.5 (Medium)


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

CWE

Assigner

mitre mitre root

References

8 references

URL	Tags
https://github.com/squid-cache/squid/security/adv…
http://www.squid-cache.org/Versions/v5/changesets…
http://www.squid-cache.org/Versions/v4/changesets…
https://lists.fedoraproject.org/archives/list/pac…	vendor-advisory
https://lists.fedoraproject.org/archives/list/pac…	vendor-advisory
https://lists.debian.org/debian-lts-announce/2021…	mailing-list
http://www.openwall.com/lists/oss-security/2023/10/11/3	mailing-list
http://seclists.org/fulldisclosure/2023/Oct/14	mailing-list

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "adp": [
      {
        "providerMetadata": {
          "dateUpdated": "2024-08-03T23:58:21.468Z",
          "orgId": "af854a3a-2127-422b-91ae-364da2661108",
          "shortName": "CVE"
        },
        "references": [
          {
            "tags": [
              "x_transferred"
            ],
            "url": "https://github.com/squid-cache/squid/security/advisories/GHSA-572g-rvwr-6c7f"
          },
          {
            "tags": [
              "x_transferred"
            ],
            "url": "http://www.squid-cache.org/Versions/v5/changesets/squid-5-8af775ed98bfd610f9ce762fe177e01b2675588c.patch"
          },
          {
            "tags": [
              "x_transferred"
            ],
            "url": "http://www.squid-cache.org/Versions/v4/changesets/squid-4-1e05a85bd28c22c9ca5d3ac9f5e86d6269ec0a8c.patch"
          },
          {
            "name": "FEDORA-2021-c0bec55ec7",
            "tags": [
              "vendor-advisory",
              "x_transferred"
            ],
            "url": "https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/LSQ3U54ZCNXR44QRPW3AV2VCS6K3TKCF/"
          },
          {
            "name": "FEDORA-2021-24af72ff2c",
            "tags": [
              "vendor-advisory",
              "x_transferred"
            ],
            "url": "https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/T4EPIWUZDJAXADDHVOPKRBTQHPBR6H66/"
          },
          {
            "name": "[debian-lts-announce] 20210614 [SECURITY] [DLA 2685-1] squid3 security update",
            "tags": [
              "mailing-list",
              "x_transferred"
            ],
            "url": "https://lists.debian.org/debian-lts-announce/2021/06/msg00014.html"
          },
          {
            "name": "[oss-security] 20231011 Squid Caching Proxy Security Audit: 55 Vulnerabilities, 35 0days.",
            "tags": [
              "mailing-list",
              "x_transferred"
            ],
            "url": "http://www.openwall.com/lists/oss-security/2023/10/11/3"
          },
          {
            "name": "20231016 Squid Caching Proxy Security Audit: 55 Vulnerabilities, 35 0days.",
            "tags": [
              "mailing-list",
              "x_transferred"
            ],
            "url": "http://seclists.org/fulldisclosure/2023/Oct/14"
          }
        ],
        "title": "CVE Program Container"
      }
    ],
    "cna": {
      "affected": [
        {
          "product": "n/a",
          "vendor": "n/a",
          "versions": [
            {
              "status": "affected",
              "version": "n/a"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "Squid before 4.15 and 5.x before 5.0.6 allows remote servers to cause a denial of service (affecting availability to all clients) via an HTTP response. The issue trigger is a header that can be expected to exist in HTTP traffic without any malicious intent by the server."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "attackComplexity": "LOW",
            "attackVector": "NETWORK",
            "availabilityImpact": "HIGH",
            "baseScore": 6.5,
            "baseSeverity": "MEDIUM",
            "confidentialityImpact": "NONE",
            "integrityImpact": "NONE",
            "privilegesRequired": "LOW",
            "scope": "UNCHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AC:L/AV:N/A:H/C:N/I:N/PR:L/S:U/UI:N",
            "version": "3.1"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "description": "n/a",
              "lang": "en",
              "type": "text"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2023-10-17T04:06:14.805Z",
        "orgId": "8254265b-2729-46b6-b9e3-3dfca2d5bfca",
        "shortName": "mitre"
      },
      "references": [
        {
          "url": "https://github.com/squid-cache/squid/security/advisories/GHSA-572g-rvwr-6c7f"
        },
        {
          "url": "http://www.squid-cache.org/Versions/v5/changesets/squid-5-8af775ed98bfd610f9ce762fe177e01b2675588c.patch"
        },
        {
          "url": "http://www.squid-cache.org/Versions/v4/changesets/squid-4-1e05a85bd28c22c9ca5d3ac9f5e86d6269ec0a8c.patch"
        },
        {
          "name": "FEDORA-2021-c0bec55ec7",
          "tags": [
            "vendor-advisory"
          ],
          "url": "https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/LSQ3U54ZCNXR44QRPW3AV2VCS6K3TKCF/"
        },
        {
          "name": "FEDORA-2021-24af72ff2c",
          "tags": [
            "vendor-advisory"
          ],
          "url": "https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/T4EPIWUZDJAXADDHVOPKRBTQHPBR6H66/"
        },
        {
          "name": "[debian-lts-announce] 20210614 [SECURITY] [DLA 2685-1] squid3 security update",
          "tags": [
            "mailing-list"
          ],
          "url": "https://lists.debian.org/debian-lts-announce/2021/06/msg00014.html"
        },
        {
          "name": "[oss-security] 20231011 Squid Caching Proxy Security Audit: 55 Vulnerabilities, 35 0days.",
          "tags": [
            "mailing-list"
          ],
          "url": "http://www.openwall.com/lists/oss-security/2023/10/11/3"
        },
        {
          "name": "20231016 Squid Caching Proxy Security Audit: 55 Vulnerabilities, 35 0days.",
          "tags": [
            "mailing-list"
          ],
          "url": "http://seclists.org/fulldisclosure/2023/Oct/14"
        }
      ]
    }
  },
  "cveMetadata": {
    "assignerOrgId": "8254265b-2729-46b6-b9e3-3dfca2d5bfca",
    "assignerShortName": "mitre",
    "cveId": "CVE-2021-33620",
    "datePublished": "2021-05-28T00:00:00.000Z",
    "dateReserved": "2021-05-28T00:00:00.000Z",
    "dateUpdated": "2024-08-03T23:58:21.468Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.1"
}

USN-4981-1 (UBUNTU-CVE-2021-28651)

Vulnerability from osv_ubuntu – Published: 2021-06-03 16:24 – Updated: 2026-04-27 14:11 – Source website

Summary

squid, squid3 vulnerabilities

Details

Joshua Rogers discovered that Squid incorrectly handled requests with the urn: scheme. A remote attacker could possibly use this issue to cause Squid to consume resources, leading to a denial of service. (CVE-2021-28651)

Joshua Rogers discovered that Squid incorrectly handled requests to the Cache Manager API. A remote attacker with access privileges could possibly use this issue to cause Squid to consume resources, leading to a denial of service. This issue was only addressed in Ubuntu 20.04 LTS, Ubuntu 20.10, and Ubuntu 21.04. (CVE-2021-28652)

Joshua Rogers discovered that Squid incorrectly handled certain response headers. A remote attacker could possibly use this issue to cause Squid to crash, resulting in a denial of service. This issue was only affected Ubuntu 20.04 LTS, Ubuntu 20.10, and Ubuntu 21.04. (CVE-2021-28662)

Joshua Rogers discovered that Squid incorrectly handled range request processing. A remote attacker could possibly use this issue to cause Squid to crash, resulting in a denial of service. (CVE-2021-31806, CVE-2021-31807, CVE-2021-31808)

Joshua Rogers discovered that Squid incorrectly handled certain HTTP responses. A remote attacker could possibly use this issue to cause Squid to crash, resulting in a denial of service. (CVE-2021-33620)

References

URL

Type

	https://ubuntu.com/security/notices/USN-4981-1	ADVISORY
	https://ubuntu.com/security/CVE-2021-28651	REPORT
	https://ubuntu.com/security/CVE-2021-28652	REPORT
	https://ubuntu.com/security/CVE-2021-28662	REPORT
	https://ubuntu.com/security/CVE-2021-31806	REPORT
	https://ubuntu.com/security/CVE-2021-31807	REPORT
	https://ubuntu.com/security/CVE-2021-31808	REPORT
	https://ubuntu.com/security/CVE-2021-33620	REPORT

JSON

To clipboard

{
  "affected": [
    {
      "database_specific": {
        "cves_map": {
          "cves": [
            {
              "id": "CVE-2021-28651",
              "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"
                }
              ]
            },
            {
              "id": "CVE-2021-28652",
              "severity": [
                {
                  "score": "CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H",
                  "type": "CVSS_V3"
                },
                {
                  "score": "low",
                  "type": "Ubuntu"
                }
              ]
            },
            {
              "id": "CVE-2021-31806",
              "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-2021-31807",
              "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-2021-31808",
              "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-2021-33620",
              "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": "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"
                }
              ]
            }
          ],
          "ecosystem": "Ubuntu:18.04:LTS"
        }
      },
      "ecosystem_specific": {
        "availability": "No subscription required",
        "binaries": [
          {
            "binary_name": "squid",
            "binary_version": "3.5.27-1ubuntu1.11"
          },
          {
            "binary_name": "squid-cgi",
            "binary_version": "3.5.27-1ubuntu1.11"
          },
          {
            "binary_name": "squid-common",
            "binary_version": "3.5.27-1ubuntu1.11"
          },
          {
            "binary_name": "squid-purge",
            "binary_version": "3.5.27-1ubuntu1.11"
          },
          {
            "binary_name": "squid3",
            "binary_version": "3.5.27-1ubuntu1.11"
          },
          {
            "binary_name": "squidclient",
            "binary_version": "3.5.27-1ubuntu1.11"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:18.04:LTS",
        "name": "squid3",
        "purl": "pkg:deb/ubuntu/squid3@3.5.27-1ubuntu1.11?arch=source\u0026distro=bionic"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "3.5.27-1ubuntu1.11"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "3.5.23-5ubuntu1",
        "3.5.23-5ubuntu2",
        "3.5.27-1ubuntu1",
        "3.5.27-1ubuntu1.1",
        "3.5.27-1ubuntu1.2",
        "3.5.27-1ubuntu1.3",
        "3.5.27-1ubuntu1.4",
        "3.5.27-1ubuntu1.5",
        "3.5.27-1ubuntu1.6",
        "3.5.27-1ubuntu1.7",
        "3.5.27-1ubuntu1.8",
        "3.5.27-1ubuntu1.9",
        "3.5.27-1ubuntu1.10"
      ]
    },
    {
      "database_specific": {
        "cves_map": {
          "cves": [
            {
              "id": "CVE-2021-28651",
              "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"
                }
              ]
            },
            {
              "id": "CVE-2021-28652",
              "severity": [
                {
                  "score": "CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H",
                  "type": "CVSS_V3"
                },
                {
                  "score": "low",
                  "type": "Ubuntu"
                }
              ]
            },
            {
              "id": "CVE-2021-28662",
              "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": "medium",
                  "type": "Ubuntu"
                }
              ]
            },
            {
              "id": "CVE-2021-31806",
              "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-2021-31807",
              "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-2021-31808",
              "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-2021-33620",
              "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": "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"
                }
              ]
            }
          ],
          "ecosystem": "Ubuntu:20.04:LTS"
        }
      },
      "ecosystem_specific": {
        "availability": "No subscription required",
        "binaries": [
          {
            "binary_name": "squid",
            "binary_version": "4.10-1ubuntu1.4"
          },
          {
            "binary_name": "squid-cgi",
            "binary_version": "4.10-1ubuntu1.4"
          },
          {
            "binary_name": "squid-common",
            "binary_version": "4.10-1ubuntu1.4"
          },
          {
            "binary_name": "squid-purge",
            "binary_version": "4.10-1ubuntu1.4"
          },
          {
            "binary_name": "squidclient",
            "binary_version": "4.10-1ubuntu1.4"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:20.04:LTS",
        "name": "squid",
        "purl": "pkg:deb/ubuntu/squid@4.10-1ubuntu1.4?arch=source\u0026distro=focal"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "4.10-1ubuntu1.4"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "4.8-1ubuntu2",
        "4.8-1ubuntu3",
        "4.9-2ubuntu1",
        "4.9-2ubuntu2",
        "4.9-2ubuntu3",
        "4.9-2ubuntu4",
        "4.10-1ubuntu1",
        "4.10-1ubuntu1.1",
        "4.10-1ubuntu1.2",
        "4.10-1ubuntu1.3"
      ]
    }
  ],
  "aliases": [],
  "details": "Joshua Rogers discovered that Squid incorrectly handled requests with the\nurn: scheme. A remote attacker could possibly use this issue to cause\nSquid to consume resources, leading to a denial of service.\n(CVE-2021-28651)\n\nJoshua Rogers discovered that Squid incorrectly handled requests to the\nCache Manager API. A remote attacker with access privileges could possibly\nuse this issue to cause Squid to consume resources, leading to a denial of\nservice. This issue was only addressed in Ubuntu 20.04 LTS, Ubuntu 20.10,\nand Ubuntu 21.04. (CVE-2021-28652)\n\nJoshua Rogers discovered that Squid incorrectly handled certain response\nheaders. A remote attacker could possibly use this issue to cause Squid to\ncrash, resulting in a denial of service. This issue was only affected\nUbuntu 20.04 LTS, Ubuntu 20.10, and Ubuntu 21.04. (CVE-2021-28662)\n\nJoshua Rogers discovered that Squid incorrectly handled range request\nprocessing. A remote attacker could possibly use this issue to cause Squid\nto crash, resulting in a denial of service. (CVE-2021-31806,\nCVE-2021-31807, CVE-2021-31808)\n\nJoshua Rogers discovered that Squid incorrectly handled certain HTTP\nresponses. A remote attacker could possibly use this issue to cause Squid\nto crash, resulting in a denial of service. (CVE-2021-33620)\n",
  "id": "USN-4981-1",
  "modified": "2026-04-27T14:11:27Z",
  "published": "2021-06-03T16:24:27Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://ubuntu.com/security/notices/USN-4981-1"
    },
    {
      "type": "REPORT",
      "url": "https://ubuntu.com/security/CVE-2021-28651"
    },
    {
      "type": "REPORT",
      "url": "https://ubuntu.com/security/CVE-2021-28652"
    },
    {
      "type": "REPORT",
      "url": "https://ubuntu.com/security/CVE-2021-28662"
    },
    {
      "type": "REPORT",
      "url": "https://ubuntu.com/security/CVE-2021-31806"
    },
    {
      "type": "REPORT",
      "url": "https://ubuntu.com/security/CVE-2021-31807"
    },
    {
      "type": "REPORT",
      "url": "https://ubuntu.com/security/CVE-2021-31808"
    },
    {
      "type": "REPORT",
      "url": "https://ubuntu.com/security/CVE-2021-33620"
    }
  ],
  "related": [],
  "schema_version": "1.7.0",
  "summary": "squid, squid3 vulnerabilities",
  "upstream": [
    "UBUNTU-CVE-2021-28651",
    "UBUNTU-CVE-2021-28652",
    "UBUNTU-CVE-2021-28662",
    "UBUNTU-CVE-2021-31806",
    "UBUNTU-CVE-2021-31807",
    "UBUNTU-CVE-2021-31808",
    "UBUNTU-CVE-2021-33620"
  ]
}

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.

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

UBUNTU-CVE-2021-33620 (CVE-2021-33620)

CVE-2021-33620 (GCVE-0-2021-33620)

USN-4981-1 (UBUNTU-CVE-2021-28651)

Tags

Sightings

Nomenclature

Related by attack behaviour