CVE-2019-12520 (GCVE-0-2019-12520)

Vulnerability from cvelistv5 – Published: 2020-04-15 19:14 – Updated: 2024-08-04 23:24
VLAI
Summary
An issue was discovered in Squid through 4.7 and 5. When receiving a request, Squid checks its cache to see if it can serve up a response. It does this by making a MD5 hash of the absolute URL of the request. If found, it servers the request. The absolute URL can include the decoded UserInfo (username and password) for certain protocols. This decoded info is prepended to the domain. This allows an attacker to provide a username that has special characters to delimit the domain, and treat the rest of the URL as a path or query string. An attacker could first make a request to their domain using an encoded username, then when a request for the target domain comes in that decodes to the exact URL, it will serve the attacker's HTML instead of the real HTML. On Squid servers that also act as reverse proxies, this allows an attacker to gain access to features that only reverse proxies can use, such as ESI.
Severity
7.5 (High)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
CWE
  • n/a
Assigner
mitre CNA under the mitre root
CNA scorecard E 29/100 over 2132 records in the last 180 days details
References
Show details on NVD website
To clipboard 

{
  "containers": {
    "adp": [
      {
        "providerMetadata": {
          "dateUpdated": "2024-08-04T23:24:38.487Z",
          "orgId": "af854a3a-2127-422b-91ae-364da2661108",
          "shortName": "CVE"
        },
        "references": [
          {
            "tags": [
              "x_refsource_MISC",
              "x_transferred"
            ],
            "url": "http://www.squid-cache.org/Versions/v4/"
          },
          {
            "tags": [
              "x_refsource_MISC",
              "x_transferred"
            ],
            "url": "http://www.squid-cache.org/Versions/v4/changesets/"
          },
          {
            "tags": [
              "x_refsource_MISC",
              "x_transferred"
            ],
            "url": "https://github.com/squid-cache/squid/commits/v4"
          },
          {
            "tags": [
              "x_refsource_MISC",
              "x_transferred"
            ],
            "url": "https://gitlab.com/jeriko.one/security/-/blob/master/squid/CVEs/CVE-2019-12520.txt"
          },
          {
            "name": "DSA-4682",
            "tags": [
              "vendor-advisory",
              "x_refsource_DEBIAN",
              "x_transferred"
            ],
            "url": "https://www.debian.org/security/2020/dsa-4682"
          },
          {
            "name": "[debian-lts-announce] 20200710 [SECURITY] [DLA 2278-1] squid3 security update",
            "tags": [
              "mailing-list",
              "x_refsource_MLIST",
              "x_transferred"
            ],
            "url": "https://lists.debian.org/debian-lts-announce/2020/07/msg00009.html"
          },
          {
            "name": "USN-4446-1",
            "tags": [
              "vendor-advisory",
              "x_refsource_UBUNTU",
              "x_transferred"
            ],
            "url": "https://usn.ubuntu.com/4446-1/"
          },
          {
            "tags": [
              "x_refsource_CONFIRM",
              "x_transferred"
            ],
            "url": "https://security.netapp.com/advisory/ntap-20210205-0006/"
          }
        ],
        "title": "CVE Program Container"
      }
    ],
    "cna": {
      "affected": [
        {
          "product": "n/a",
          "vendor": "n/a",
          "versions": [
            {
              "status": "affected",
              "version": "n/a"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "An issue was discovered in Squid through 4.7 and 5. When receiving a request, Squid checks its cache to see if it can serve up a response. It does this by making a MD5 hash of the absolute URL of the request. If found, it servers the request. The absolute URL can include the decoded UserInfo (username and password) for certain protocols. This decoded info is prepended to the domain. This allows an attacker to provide a username that has special characters to delimit the domain, and treat the rest of the URL as a path or query string. An attacker could first make a request to their domain using an encoded username, then when a request for the target domain comes in that decodes to the exact URL, it will serve the attacker\u0027s HTML instead of the real HTML. On Squid servers that also act as reverse proxies, this allows an attacker to gain access to features that only reverse proxies can use, such as ESI."
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "description": "n/a",
              "lang": "en",
              "type": "text"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2021-02-05T11:06:17.000Z",
        "orgId": "8254265b-2729-46b6-b9e3-3dfca2d5bfca",
        "shortName": "mitre"
      },
      "references": [
        {
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "http://www.squid-cache.org/Versions/v4/"
        },
        {
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "http://www.squid-cache.org/Versions/v4/changesets/"
        },
        {
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/squid-cache/squid/commits/v4"
        },
        {
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://gitlab.com/jeriko.one/security/-/blob/master/squid/CVEs/CVE-2019-12520.txt"
        },
        {
          "name": "DSA-4682",
          "tags": [
            "vendor-advisory",
            "x_refsource_DEBIAN"
          ],
          "url": "https://www.debian.org/security/2020/dsa-4682"
        },
        {
          "name": "[debian-lts-announce] 20200710 [SECURITY] [DLA 2278-1] squid3 security update",
          "tags": [
            "mailing-list",
            "x_refsource_MLIST"
          ],
          "url": "https://lists.debian.org/debian-lts-announce/2020/07/msg00009.html"
        },
        {
          "name": "USN-4446-1",
          "tags": [
            "vendor-advisory",
            "x_refsource_UBUNTU"
          ],
          "url": "https://usn.ubuntu.com/4446-1/"
        },
        {
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://security.netapp.com/advisory/ntap-20210205-0006/"
        }
      ],
      "x_legacyV4Record": {
        "CVE_data_meta": {
          "ASSIGNER": "cve@mitre.org",
          "ID": "CVE-2019-12520",
          "STATE": "PUBLIC"
        },
        "affects": {
          "vendor": {
            "vendor_data": [
              {
                "product": {
                  "product_data": [
                    {
                      "product_name": "n/a",
                      "version": {
                        "version_data": [
                          {
                            "version_value": "n/a"
                          }
                        ]
                      }
                    }
                  ]
                },
                "vendor_name": "n/a"
              }
            ]
          }
        },
        "data_format": "MITRE",
        "data_type": "CVE",
        "data_version": "4.0",
        "description": {
          "description_data": [
            {
              "lang": "eng",
              "value": "An issue was discovered in Squid through 4.7 and 5. When receiving a request, Squid checks its cache to see if it can serve up a response. It does this by making a MD5 hash of the absolute URL of the request. If found, it servers the request. The absolute URL can include the decoded UserInfo (username and password) for certain protocols. This decoded info is prepended to the domain. This allows an attacker to provide a username that has special characters to delimit the domain, and treat the rest of the URL as a path or query string. An attacker could first make a request to their domain using an encoded username, then when a request for the target domain comes in that decodes to the exact URL, it will serve the attacker\u0027s HTML instead of the real HTML. On Squid servers that also act as reverse proxies, this allows an attacker to gain access to features that only reverse proxies can use, such as ESI."
            }
          ]
        },
        "problemtype": {
          "problemtype_data": [
            {
              "description": [
                {
                  "lang": "eng",
                  "value": "n/a"
                }
              ]
            }
          ]
        },
        "references": {
          "reference_data": [
            {
              "name": "http://www.squid-cache.org/Versions/v4/",
              "refsource": "MISC",
              "url": "http://www.squid-cache.org/Versions/v4/"
            },
            {
              "name": "http://www.squid-cache.org/Versions/v4/changesets/",
              "refsource": "MISC",
              "url": "http://www.squid-cache.org/Versions/v4/changesets/"
            },
            {
              "name": "https://github.com/squid-cache/squid/commits/v4",
              "refsource": "MISC",
              "url": "https://github.com/squid-cache/squid/commits/v4"
            },
            {
              "name": "https://gitlab.com/jeriko.one/security/-/blob/master/squid/CVEs/CVE-2019-12520.txt",
              "refsource": "MISC",
              "url": "https://gitlab.com/jeriko.one/security/-/blob/master/squid/CVEs/CVE-2019-12520.txt"
            },
            {
              "name": "DSA-4682",
              "refsource": "DEBIAN",
              "url": "https://www.debian.org/security/2020/dsa-4682"
            },
            {
              "name": "[debian-lts-announce] 20200710 [SECURITY] [DLA 2278-1] squid3 security update",
              "refsource": "MLIST",
              "url": "https://lists.debian.org/debian-lts-announce/2020/07/msg00009.html"
            },
            {
              "name": "USN-4446-1",
              "refsource": "UBUNTU",
              "url": "https://usn.ubuntu.com/4446-1/"
            },
            {
              "name": "https://security.netapp.com/advisory/ntap-20210205-0006/",
              "refsource": "CONFIRM",
              "url": "https://security.netapp.com/advisory/ntap-20210205-0006/"
            }
          ]
        }
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "8254265b-2729-46b6-b9e3-3dfca2d5bfca",
    "assignerShortName": "mitre",
    "cveId": "CVE-2019-12520",
    "datePublished": "2020-04-15T19:14:25.000Z",
    "dateReserved": "2019-06-02T00:00:00.000Z",
    "dateUpdated": "2024-08-04T23:24:38.487Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.1",
  "vulnerability-lookup:meta": {
    "epss": {
      "cve": "CVE-2019-12520",
      "date": "2026-11-14",
      "epss": "0.03924",
      "percentile": "0.9052"
    },
    "fkie_nvd": {
      "configurations": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:a:squid-cache:squid:*:*:*:*:*:*:*:*",
                  "matchCriteriaId": "A5584C95-5CB1-4D45-8C05-633746AE2AB4",
                  "versionEndIncluding": "4.7",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        },
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:canonical:ubuntu_linux:16.04:*:*:*:lts:*:*:*",
                  "matchCriteriaId": "F7016A2A-8365-4F1A-89A2-7A19F2BCAE5B",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:canonical:ubuntu_linux:18.04:*:*:*:lts:*:*:*",
                  "matchCriteriaId": "23A7C53F-B80F-4E6A-AFA9-58EEA84BE11D",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        },
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:*",
                  "matchCriteriaId": "DEECE5FC-CACF-4496-A3E7-164736409252",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:*",
                  "matchCriteriaId": "07B237A9-69A3-4A9C-9DA0-4E06BD37AE73",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "An issue was discovered in Squid through 4.7 and 5. When receiving a request, Squid checks its cache to see if it can serve up a response. It does this by making a MD5 hash of the absolute URL of the request. If found, it servers the request. The absolute URL can include the decoded UserInfo (username and password) for certain protocols. This decoded info is prepended to the domain. This allows an attacker to provide a username that has special characters to delimit the domain, and treat the rest of the URL as a path or query string. An attacker could first make a request to their domain using an encoded username, then when a request for the target domain comes in that decodes to the exact URL, it will serve the attacker\u0027s HTML instead of the real HTML. On Squid servers that also act as reverse proxies, this allows an attacker to gain access to features that only reverse proxies can use, such as ESI."
        },
        {
          "lang": "es",
          "value": "Se descubri\u00f3  un problema en Squid versiones hasta 4.7 y 5. Cuando se recibe una petici\u00f3n, Squid comprueba su memoria cach\u00e9 para visualizar si puede servir una respuesta. Lo hace al realizar un hash MD5 de la URL absoluta de la petici\u00f3n. Si se encuentra, sirve la petici\u00f3n. La URL absoluta puede incluir la UserInfo decodificada (nombre de usuario y contrase\u00f1a) para determinados protocolos. Esta informaci\u00f3n decodificada se antepone al dominio. Esto permite a un atacante proporcionar un nombre de usuario que tenga caracteres especiales para delimitar el dominio y tratar el resto de la URL como una ruta o cadena de consulta. Un atacante podr\u00eda primero hacer una petici\u00f3n a su dominio usando un nombre de usuario codificado, luego, cuando llega una petici\u00f3n para el dominio objetivo que decodifica a la URL exacta, servir\u00e1 el HTML del atacante en lugar del HTML real. En los servidores de Squid que tambi\u00e9n act\u00faan como proxies inversos, esto permite a un atacante conseguir acceso a funcionalidades que solo los proxies inversos pueden utilizar, tal y como ESI."
        }
      ],
      "id": "CVE-2019-12520",
      "lastModified": "2024-11-21T04:23:01.370",
      "metrics": {
        "cvssMetricV2": [
          {
            "acInsufInfo": false,
            "baseSeverity": "MEDIUM",
            "cvssData": {
              "accessComplexity": "LOW",
              "accessVector": "NETWORK",
              "authentication": "NONE",
              "availabilityImpact": "NONE",
              "baseScore": 5.0,
              "confidentialityImpact": "PARTIAL",
              "integrityImpact": "NONE",
              "vectorString": "AV:N/AC:L/Au:N/C:P/I:N/A:N",
              "version": "2.0"
            },
            "exploitabilityScore": 10.0,
            "impactScore": 2.9,
            "obtainAllPrivilege": false,
            "obtainOtherPrivilege": false,
            "obtainUserPrivilege": false,
            "source": "nvd@nist.gov",
            "type": "Primary",
            "userInteractionRequired": false
          }
        ],
        "cvssMetricV31": [
          {
            "cvssData": {
              "attackComplexity": "LOW",
              "attackVector": "NETWORK",
              "availabilityImpact": "NONE",
              "baseScore": 7.5,
              "baseSeverity": "HIGH",
              "confidentialityImpact": "HIGH",
              "integrityImpact": "NONE",
              "privilegesRequired": "NONE",
              "scope": "UNCHANGED",
              "userInteraction": "NONE",
              "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N",
              "version": "3.1"
            },
            "exploitabilityScore": 3.9,
            "impactScore": 3.6,
            "source": "nvd@nist.gov",
            "type": "Primary"
          }
        ]
      },
      "published": "2020-04-15T20:15:13.520",
      "references": [
        {
          "source": "cve@mitre.org",
          "tags": [
            "Release Notes",
            "Vendor Advisory"
          ],
          "url": "http://www.squid-cache.org/Versions/v4/"
        },
        {
          "source": "cve@mitre.org",
          "tags": [
            "Release Notes",
            "Vendor Advisory"
          ],
          "url": "http://www.squid-cache.org/Versions/v4/changesets/"
        },
        {
          "source": "cve@mitre.org",
          "tags": [
            "Patch",
            "Third Party Advisory"
          ],
          "url": "https://github.com/squid-cache/squid/commits/v4"
        },
        {
          "source": "cve@mitre.org",
          "tags": [
            "Third Party Advisory"
          ],
          "url": "https://gitlab.com/jeriko.one/security/-/blob/master/squid/CVEs/CVE-2019-12520.txt"
        },
        {
          "source": "cve@mitre.org",
          "tags": [
            "Mailing List",
            "Third Party Advisory"
          ],
          "url": "https://lists.debian.org/debian-lts-announce/2020/07/msg00009.html"
        },
        {
          "source": "cve@mitre.org",
          "tags": [
            "Third Party Advisory"
          ],
          "url": "https://security.netapp.com/advisory/ntap-20210205-0006/"
        },
        {
          "source": "cve@mitre.org",
          "tags": [
            "Third Party Advisory"
          ],
          "url": "https://usn.ubuntu.com/4446-1/"
        },
        {
          "source": "cve@mitre.org",
          "tags": [
            "Third Party Advisory"
          ],
          "url": "https://www.debian.org/security/2020/dsa-4682"
        },
        {
          "source": "af854a3a-2127-422b-91ae-364da2661108",
          "tags": [
            "Release Notes",
            "Vendor Advisory"
          ],
          "url": "http://www.squid-cache.org/Versions/v4/"
        },
        {
          "source": "af854a3a-2127-422b-91ae-364da2661108",
          "tags": [
            "Release Notes",
            "Vendor Advisory"
          ],
          "url": "http://www.squid-cache.org/Versions/v4/changesets/"
        },
        {
          "source": "af854a3a-2127-422b-91ae-364da2661108",
          "tags": [
            "Patch",
            "Third Party Advisory"
          ],
          "url": "https://github.com/squid-cache/squid/commits/v4"
        },
        {
          "source": "af854a3a-2127-422b-91ae-364da2661108",
          "tags": [
            "Third Party Advisory"
          ],
          "url": "https://gitlab.com/jeriko.one/security/-/blob/master/squid/CVEs/CVE-2019-12520.txt"
        },
        {
          "source": "af854a3a-2127-422b-91ae-364da2661108",
          "tags": [
            "Mailing List",
            "Third Party Advisory"
          ],
          "url": "https://lists.debian.org/debian-lts-announce/2020/07/msg00009.html"
        },
        {
          "source": "af854a3a-2127-422b-91ae-364da2661108",
          "tags": [
            "Third Party Advisory"
          ],
          "url": "https://security.netapp.com/advisory/ntap-20210205-0006/"
        },
        {
          "source": "af854a3a-2127-422b-91ae-364da2661108",
          "tags": [
            "Third Party Advisory"
          ],
          "url": "https://usn.ubuntu.com/4446-1/"
        },
        {
          "source": "af854a3a-2127-422b-91ae-364da2661108",
          "tags": [
            "Third Party Advisory"
          ],
          "url": "https://www.debian.org/security/2020/dsa-4682"
        }
      ],
      "sourceIdentifier": "cve@mitre.org",
      "vulnStatus": "Modified",
      "weaknesses": [
        {
          "description": [
            {
              "lang": "en",
              "value": "CWE-20"
            }
          ],
          "source": "nvd@nist.gov",
          "type": "Primary"
        }
      ]
    },
    "nvd": {
      "cve": {
        "configurations": [
          {
            "nodes": [
              {
                "cpeMatch": [
                  {
                    "criteria": "cpe:2.3:a:squid-cache:squid:*:*:*:*:*:*:*:*",
                    "matchCriteriaId": "A5584C95-5CB1-4D45-8C05-633746AE2AB4",
                    "versionEndIncluding": "4.7",
                    "vulnerable": true
                  }
                ],
                "negate": false,
                "operator": "OR"
              }
            ]
          },
          {
            "nodes": [
              {
                "cpeMatch": [
                  {
                    "criteria": "cpe:2.3:o:canonical:ubuntu_linux:16.04:*:*:*:lts:*:*:*",
                    "matchCriteriaId": "F7016A2A-8365-4F1A-89A2-7A19F2BCAE5B",
                    "vulnerable": true
                  },
                  {
                    "criteria": "cpe:2.3:o:canonical:ubuntu_linux:18.04:*:*:*:lts:*:*:*",
                    "matchCriteriaId": "23A7C53F-B80F-4E6A-AFA9-58EEA84BE11D",
                    "vulnerable": true
                  }
                ],
                "negate": false,
                "operator": "OR"
              }
            ]
          },
          {
            "nodes": [
              {
                "cpeMatch": [
                  {
                    "criteria": "cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:*",
                    "matchCriteriaId": "DEECE5FC-CACF-4496-A3E7-164736409252",
                    "vulnerable": true
                  },
                  {
                    "criteria": "cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:*",
                    "matchCriteriaId": "07B237A9-69A3-4A9C-9DA0-4E06BD37AE73",
                    "vulnerable": true
                  }
                ],
                "negate": false,
                "operator": "OR"
              }
            ]
          }
        ],
        "cveTags": [],
        "descriptions": [
          {
            "lang": "en",
            "value": "An issue was discovered in Squid through 4.7 and 5. When receiving a request, Squid checks its cache to see if it can serve up a response. It does this by making a MD5 hash of the absolute URL of the request. If found, it servers the request. The absolute URL can include the decoded UserInfo (username and password) for certain protocols. This decoded info is prepended to the domain. This allows an attacker to provide a username that has special characters to delimit the domain, and treat the rest of the URL as a path or query string. An attacker could first make a request to their domain using an encoded username, then when a request for the target domain comes in that decodes to the exact URL, it will serve the attacker\u0027s HTML instead of the real HTML. On Squid servers that also act as reverse proxies, this allows an attacker to gain access to features that only reverse proxies can use, such as ESI."
          },
          {
            "lang": "es",
            "value": "Se descubri\u00f3  un problema en Squid versiones hasta 4.7 y 5. Cuando se recibe una petici\u00f3n, Squid comprueba su memoria cach\u00e9 para visualizar si puede servir una respuesta. Lo hace al realizar un hash MD5 de la URL absoluta de la petici\u00f3n. Si se encuentra, sirve la petici\u00f3n. La URL absoluta puede incluir la UserInfo decodificada (nombre de usuario y contrase\u00f1a) para determinados protocolos. Esta informaci\u00f3n decodificada se antepone al dominio. Esto permite a un atacante proporcionar un nombre de usuario que tenga caracteres especiales para delimitar el dominio y tratar el resto de la URL como una ruta o cadena de consulta. Un atacante podr\u00eda primero hacer una petici\u00f3n a su dominio usando un nombre de usuario codificado, luego, cuando llega una petici\u00f3n para el dominio objetivo que decodifica a la URL exacta, servir\u00e1 el HTML del atacante en lugar del HTML real. En los servidores de Squid que tambi\u00e9n act\u00faan como proxies inversos, esto permite a un atacante conseguir acceso a funcionalidades que solo los proxies inversos pueden utilizar, tal y como ESI."
          }
        ],
        "id": "CVE-2019-12520",
        "lastModified": "2024-11-21T04:23:01.370",
        "metrics": {
          "cvssMetricV2": [
            {
              "acInsufInfo": false,
              "baseSeverity": "MEDIUM",
              "cvssData": {
                "accessComplexity": "LOW",
                "accessVector": "NETWORK",
                "authentication": "NONE",
                "availabilityImpact": "NONE",
                "baseScore": 5.0,
                "confidentialityImpact": "PARTIAL",
                "integrityImpact": "NONE",
                "vectorString": "AV:N/AC:L/Au:N/C:P/I:N/A:N",
                "version": "2.0"
              },
              "exploitabilityScore": 10.0,
              "impactScore": 2.9,
              "obtainAllPrivilege": false,
              "obtainOtherPrivilege": false,
              "obtainUserPrivilege": false,
              "source": "nvd@nist.gov",
              "type": "Primary",
              "userInteractionRequired": false
            }
          ],
          "cvssMetricV31": [
            {
              "cvssData": {
                "attackComplexity": "LOW",
                "attackVector": "NETWORK",
                "availabilityImpact": "NONE",
                "baseScore": 7.5,
                "baseSeverity": "HIGH",
                "confidentialityImpact": "HIGH",
                "integrityImpact": "NONE",
                "privilegesRequired": "NONE",
                "scope": "UNCHANGED",
                "userInteraction": "NONE",
                "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N",
                "version": "3.1"
              },
              "exploitabilityScore": 3.9,
              "impactScore": 3.6,
              "source": "nvd@nist.gov",
              "type": "Primary"
            }
          ]
        },
        "published": "2020-04-15T20:15:13.520",
        "references": [
          {
            "source": "cve@mitre.org",
            "tags": [
              "Release Notes",
              "Vendor Advisory"
            ],
            "url": "http://www.squid-cache.org/Versions/v4/"
          },
          {
            "source": "cve@mitre.org",
            "tags": [
              "Release Notes",
              "Vendor Advisory"
            ],
            "url": "http://www.squid-cache.org/Versions/v4/changesets/"
          },
          {
            "source": "cve@mitre.org",
            "tags": [
              "Patch",
              "Third Party Advisory"
            ],
            "url": "https://github.com/squid-cache/squid/commits/v4"
          },
          {
            "source": "cve@mitre.org",
            "tags": [
              "Third Party Advisory"
            ],
            "url": "https://gitlab.com/jeriko.one/security/-/blob/master/squid/CVEs/CVE-2019-12520.txt"
          },
          {
            "source": "cve@mitre.org",
            "tags": [
              "Mailing List",
              "Third Party Advisory"
            ],
            "url": "https://lists.debian.org/debian-lts-announce/2020/07/msg00009.html"
          },
          {
            "source": "cve@mitre.org",
            "tags": [
              "Third Party Advisory"
            ],
            "url": "https://security.netapp.com/advisory/ntap-20210205-0006/"
          },
          {
            "source": "cve@mitre.org",
            "tags": [
              "Third Party Advisory"
            ],
            "url": "https://usn.ubuntu.com/4446-1/"
          },
          {
            "source": "cve@mitre.org",
            "tags": [
              "Third Party Advisory"
            ],
            "url": "https://www.debian.org/security/2020/dsa-4682"
          },
          {
            "source": "af854a3a-2127-422b-91ae-364da2661108",
            "tags": [
              "Release Notes",
              "Vendor Advisory"
            ],
            "url": "http://www.squid-cache.org/Versions/v4/"
          },
          {
            "source": "af854a3a-2127-422b-91ae-364da2661108",
            "tags": [
              "Release Notes",
              "Vendor Advisory"
            ],
            "url": "http://www.squid-cache.org/Versions/v4/changesets/"
          },
          {
            "source": "af854a3a-2127-422b-91ae-364da2661108",
            "tags": [
              "Patch",
              "Third Party Advisory"
            ],
            "url": "https://github.com/squid-cache/squid/commits/v4"
          },
          {
            "source": "af854a3a-2127-422b-91ae-364da2661108",
            "tags": [
              "Third Party Advisory"
            ],
            "url": "https://gitlab.com/jeriko.one/security/-/blob/master/squid/CVEs/CVE-2019-12520.txt"
          },
          {
            "source": "af854a3a-2127-422b-91ae-364da2661108",
            "tags": [
              "Mailing List",
              "Third Party Advisory"
            ],
            "url": "https://lists.debian.org/debian-lts-announce/2020/07/msg00009.html"
          },
          {
            "source": "af854a3a-2127-422b-91ae-364da2661108",
            "tags": [
              "Third Party Advisory"
            ],
            "url": "https://security.netapp.com/advisory/ntap-20210205-0006/"
          },
          {
            "source": "af854a3a-2127-422b-91ae-364da2661108",
            "tags": [
              "Third Party Advisory"
            ],
            "url": "https://usn.ubuntu.com/4446-1/"
          },
          {
            "source": "af854a3a-2127-422b-91ae-364da2661108",
            "tags": [
              "Third Party Advisory"
            ],
            "url": "https://www.debian.org/security/2020/dsa-4682"
          }
        ],
        "sourceIdentifier": "cve@mitre.org",
        "vulnStatus": "Modified",
        "weaknesses": [
          {
            "description": [
              {
                "lang": "en",
                "value": "CWE-20"
              }
            ],
            "source": "nvd@nist.gov",
            "type": "Primary"
          }
        ]
      }
    },
    "redhat_vex": {
      "aggregate_severity": "Moderate",
      "current_release_date": "2026-11-05T07:27:50+00:00",
      "cve": "CVE-2019-12520",
      "id": "CVE-2019-12520",
      "initial_release_date": "2019-01-01T00:00:00+00:00",
      "product_status:fixed": "30",
      "product_status:known_affected": "9",
      "source": "Red Hat CSAF VEX",
      "status": "final",
      "title": "squid: Improper input validation in request allows for proxy manipulation",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2019/cve-2019-12520.json",
      "version": "3"
    },
    "suse_vex": {
      "aggregate_severity": "moderate",
      "current_release_date": "2026-07-31T01:39:28Z",
      "cve": "CVE-2019-12520",
      "id": "CVE-2019-12520",
      "initial_release_date": "2023-02-15T04:11:32Z",
      "product_status:known_not_affected": "20",
      "product_status:recommended": "27",
      "source": "SUSE CSAF VEX",
      "status": "interim",
      "title": "SUSE CVE CVE-2019-12520",
      "url": "https://ftp.suse.com/pub/projects/security/csaf-vex/cve-2019-12520.json",
      "version": "9"
    }
  }
}



Log in or create an account to share your comment.




Tags
Taxonomy of the tags.




Drag nodes to arrange them. Double-click a related vulnerability to open it, or a source to visit its link. The Physics button on the left tunes the layout and the simulation; the legend at the bottom left hides or shows nodes by kind and by sighting type.

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.
Vulnerability timeline

Sightings and recorded dates, grouped by day · UTC

JSON
How durations are calculated

Following the VTEM framework (Black Hat USA 2015), time to patch starts when the vendor or a coordinator was informed, total time to patch at discovery, and disclosure to patch at public disclosure; vendor response time runs from the report to its acknowledgement. Time to exploit and time unpatched start at the earliest discovery or report, falling back to public disclosure. Unpatched time ends at the first recorded patch, or the calculation time when no patch is recorded. Exploitation to patch shows the interval between those two events; a published proof of concept is a public exploit, not exploitation.

Each result shows its source dates. A negative interval means the end event came first; when date-only inputs leave the order open, the result says so. Date-only inputs are approximate. The earliest evidence wins: KEV report dates and sightings are labelled as such. Records describing another vulnerability are listed but never calculated from, and a PoC alone does not establish exploitation. Missing patch evidence does not prove that no patch exists. Filters below change the event list only.

Loading timeline…




    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.