Security advisory

{
  "id": "48b4db909ee926f1fc86181e3a902e01b5ebd75e1576a4feb2c445761adf4e41",
  "url": "https://osv.dev/vulnerability/CVE-2020-35591",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "CVE-2020-35591",
    "summary": "Pi-hole 5.0, 5.1, and 5.1.1 allows Session Fixation. The application does not generate a new session cookie after the user is logged in. A malicious user is able to create a new session cookie value and inject it to a victim. After the victim logs in, the injected cookie becomes valid, giving the attacker access to the user's account through the active session.",
    "evidence": "osv:CVE-2020-35591",
    "products": [],
    "severity": "medium",
    "structured": {
      "id": "CVE-2020-35591",
      "aliases": [
        "CVE-2020-35591"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/pi-hole/pi-hole",
              "type": "GIT",
              "events": [
                {
                  "introduced": "4d25f695267590b61a4061f9bb43448005d99b85"
                },
                {
                  "last_affected": "56cd7c4d59ceb629a2170cd1c8ab78ef26366019"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "cpe": "cpe:2.3:a:pi-hole:pi-hole:5.0:*:*:*:*:*:*:*",
                    "range": [
                      {
                        "introduced": "5.0"
                      },
                      {
                        "last_affected": "5.0"
                      }
                    ],
                    "source": "CPE_STRING"
                  },
                  {
                    "cpe": "cpe:2.3:a:pi-hole:pi-hole:5.1:*:*:*:*:*:*:*",
                    "range": [
                      {
                        "introduced": "5.1"
                      },
                      {
                        "last_affected": "5.1"
                      }
                    ],
                    "source": "CPE_STRING"
                  },
                  {
                    "cpe": "cpe:2.3:a:pi-hole:pi-hole:5.1.1:*:*:*:*:*:*:*",
                    "range": [
                      {
                        "introduced": "5.1.1"
                      },
                      {
                        "last_affected": "5.1.1"
                      }
                    ],
                    "source": "CPE_STRING"
                  }
                ]
              }
            }
          ],
          "versions": [
            "5.0",
            "5.1",
            "5.1.1",
            "v5.1.1",
            "v5.1",
            "v5.0"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2020-35591.json"
          }
        },
        {
          "ranges": [
            {
              "repo": "https://github.com/pi-hole/web",
              "type": "GIT",
              "events": [
                {
                  "introduced": "b86e4a3178e46cef9fc738c6a0fb8d0ef0ff2fbc"
                },
                {
                  "last_affected": "a03d1bddf74f0164f637126b06705bb659dfa4e7"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "cpe": "cpe:2.3:a:pi-hole:pi-hole:5.0:*:*:*:*:*:*:*",
                    "range": [
                      {
                        "introduced": "5.0"
                      },
                      {
                        "last_affected": "5.0"
                      }
                    ],
                    "source": "CPE_STRING"
                  },
                  {
                    "cpe": "cpe:2.3:a:pi-hole:pi-hole:5.1:*:*:*:*:*:*:*",
                    "range": [
                      {
                        "introduced": "5.1"
                      },
                      {
                        "last_affected": "5.1"
                      }
                    ],
                    "source": "CPE_STRING"
                  },
                  {
                    "cpe": "cpe:2.3:a:pi-hole:pi-hole:5.1.1:*:*:*:*:*:*:*",
                    "range": [
                      {
                        "introduced": "5.1.1"
                      },
                      {
                        "last_affected": "5.1.1"
                      }
                    ],
                    "source": "CPE_STRING"
                  }
                ]
              }
            }
          ],
          "versions": [
            "5.0",
            "5.1",
            "5.1.1",
            "v5.1.1",
            "v5.1",
            "v5.0"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2020-35591.json"
          }
        }
      ],
      "modified": "2026-10-24T10:31:00.638992511Z",
      "provider": "osv",
      "references": [
        "https://discourse.pi-hole.net/c/announcements/5",
        "https://n4nj0.github.io/advisories/pi-hole-multiple-vulnerabilities-i/"
      ],
      "provider_metadata": {}
    },
    "related_cves": [
      {
        "value": "CVE-2020-35591",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 439602,
  "published_at": "2021-02-18T20:15:12.29+00:00"
}