ghsa-g3hp-f6mg-559v

{
  "affected": [
    {
      "database_specific": {
        "source": "https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/05/GHSA-g3hp-f6mg-559v/GHSA-g3hp-f6mg-559v.json"
      },
      "package": {
        "ecosystem": "SwiftURL",
        "name": "github.com/sparkle-project/Sparkle",
        "purl": "pkg:swift/github.com/sparkle-project/Sparkle"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "last_affected": "2.9.1"
            }
          ],
          "type": "SEMVER"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-47122"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-306",
      "CWE-441"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-05-29T19:47:19Z",
    "nvd_published_at": null,
    "severity": "MODERATE"
  },
  "details": "## Summary\n\nAppInstaller post-stage-1 XPC listener accepts unvalidated connections, allowing spoofed appcast item data injection.\n\n## Details\n\n`Autoupdate/AppInstaller.m`'s `shouldAcceptNewConnection:` only enforces `SUCodeSigningVerifier validateConnection:` before stage 1 completes. After `_performedStage1Installation = YES`, new connections to the registered Mach service `<bundleId>-spki` are accepted from any local process without team-ID or code-signing checks.\n\nThe following chain of events enables an attacker to inject a spoofed `SPUSentUpdateAppcastItemData` payload:\n\n1. Installer finishes unarchiving the update successfully (`_willCompleteInstallation` is set).\n2. The app responsible for updating the bundle crashes or is forcefully quit before it has a chance to send `SPUSentUpdateAppcastItemData` to the installer. There is no user interaction between the prior step and this one, so the timing window is tight.\n3. After stage 1 of the installer is performed (`_performedStage1Installation = YES`), but before final installation completes (since all services are cleaned up by then), an attacker process connects to the `<bundleId>-spki` Mach service - no code-signing validation is enforced - and sends a spoofed `SPUSentUpdateAppcastItemData` message containing an attacker-crafted `SUAppcastItem`.\n4. A Sparkle-aware app that checks for updates on the bundle being updated launches before installation completes. The progress agent re-broadcasts the spoofed `SUAppcastItem` on its `<bundleId>-spks` status service, and the launching app displays attacker-controlled release notes (name, version, critical flag).\n\nNote: Sparkle can be used to update other app bundles, so the \"app doing the updating\" and the \"app being updated\" are not necessarily the same bundle.\n\nIn the system-domain case (`SPUUsesSystemDomainForBundlePath = true`), the AppInstaller runs as root via `SMJobSubmit` to `kSMDomainSystemLaunchd`, and the Mach service is reachable by any local user process.\n\nAffected versions: 2.x branch including 2.9.1.\n\n## Impact\n\nA local user-level process can inject a forged `SUAppcastItem` (arbitrary name, version, critical flag) into the progress agent's status broadcast. Other Sparkle-aware clients on the system will display attacker-controlled release notes as authoritative installation state.\n\nThe integrity of the installed code is **not** affected - the bundle moved into place is the legitimate, signature-validated update from stage 1. The impact is limited to UI spoofing of installation metadata.\n\n## Remediation\n\nEnforce `SUCodeSigningVerifier validateConnection:` on all new connections regardless of installation stage, or disallow `SPUSentUpdateAppcastItemData` after the active connection invalidates.",
  "id": "GHSA-g3hp-f6mg-559v",
  "modified": "2026-09-10T03:50:46.751806526Z",
  "published": "2026-05-29T19:47:19Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/sparkle-project/Sparkle/security/advisories/GHSA-g3hp-f6mg-559v"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/sparkle-project/Sparkle"
    }
  ],
  "schema_version": "1.9.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:N/I:L/A:L",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Sparkle's AppInstaller post-stage-1 XPC listener accepts unvalidated connections, allowing spoofed appcast item data injection"
}