CVE-2025-46336: Rack session Rack Session Gets Restored After Vulnerability

{
  "schema_version" : "1.4.0",
  "id" : "GHSA-9j94-67jr-4cqj",
  "modified" : "2025-05-09T14:34:48Z",
  "published" : "2025-05-08T14:45:33Z",
  "aliases" : [ "CVE-2025-46336" ],
  "summary" : "Rack session gets restored after deletion",
  "details" : "## Summary\n\nWhen using the `Rack::Session::Pool` middleware, simultaneous rack requests can restore a deleted rack session, which allows the unauthenticated user to occupy that session.\n\n## Details\n\n[Rack session middleware](https://github.com/rack/rack-session/blob/v2.1.0/lib/rack/session/abstract/id.rb#L271-L278) prepares the session at the beginning of request, then saves is back to the store with possible changes applied by host rack application. This way the session becomes to be a subject of race conditions in general sense over concurrent rack requests.\n\n## Impact\n\nWhen using the `Rack::Session::Pool` middleware, and provided the attacker can acquire a session cookie (already a major issue), the session may be restored if the attacker can trigger a long running request (within that same session) adjacent to the user logging out, in order to retain illicit access even after a user has attempted to logout.\n\n## Mitigation\n\n- Update to the latest version of `rack-session`, or\n- Ensure your application invalidates sessions atomically by marking them as logged out e.g., using a `logged_out` flag, instead of deleting them, and check this flag on every request to prevent reuse, or\n- Implement a custom session store that tracks session invalidation timestamps and refuses to accept session data if the session was invalidated after the request began.\n\n## Related\n\nThis code was previously part of `rack` in Rack < 3, see <https://github.com/rack/rack/security/advisories/GHSA-vpfw-47h7-xj4g> for the equivalent advisory in `rack` (affecting Rack < 3 only).",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "RubyGems",
      "name" : "rack-session"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "2.0.0"
      }, {
        "fixed" : "2.1.1"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/rack/rack-session/security/advisories/GHSA-9j94-67jr-4cqj"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/rack/rack/security/advisories/GHSA-vpfw-47h7-xj4g"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2025-46336"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/rack/rack-session/commit/c28c4a8c1861d814e09f2ae48264ac4c40be2d3b"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/rack/rack-session"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/rubysec/ruby-advisory-db/blob/master/gems/rack-session/CVE-2025-46336.yml"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-362", "CWE-367", "CWE-613" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2025-05-08T14:45:33Z",
    "nvd_published_at" : "2025-05-08T20:15:30Z"
  }
}