| パッケージ | 影響を受けるバージョン | 修正済みバージョン |
|---|---|---|
| github.com/cloudreve/Cloudreve | 全バージョン | |
| github.com/cloudreve/Cloudreve/v3 | ≤ 3.0.0-20250225100611-da4e44b77af4全バージョン | |
| github.com/cloudreve/Cloudreve/v4 | < 4.0.0-20260613030215-0b00dd308f13 | 4.0.0-20260613030215-0b00dd308f13 |
When an authenticated recipient of a single-file share opens the file event stream (GET /api/v4/file/events?uri=<share-root>), Cloudreve validates the URI by listing it and then subscribes the caller to parent.ID(). For a single-file share, the share navigator resolves the bare share-root URI to the owner-side parent folder of the shared file (not the file), while the visible listing is filtered down to just the shared file. The event hub then keys topics by numeric file ID only and, on each file change, fans the event out to subscribers of every ancestor topic, filtering only the client ID that caused the event — never the subscriber's share scope.
Consequently, a recipient of one shared file can receive Server-Sent Events (type, sibling path/name, rename target, hashed file ID) for other files and subfolders in the owner's parent folder that were never shared. Contents are not disclosed; file-activity metadata is.
26b6b10)1. Events route — authenticated, feature-flagged, no share-scope check (routers/router.go):
file := v4.Group("file"); file.Use(middleware.RequiredScopes(types.ScopeFilesRead))
file.GET("events",
middleware.LoginRequired(),
middleware.IsFunctionEnabled(func(c *gin.Context) bool { return dep.SettingProvider().EventHubEnabled(c) }),
controllers.FromQuery[explorer.ExplorerEventService](...), controllers.HandleExplorerEventsPush)
EventHubEnabled defaults true (inventory/setting.go: "fs_event_push_enabled":"1").
2. Service subscribes to the listed parent's ID (service/explorer/events.go):
parent, _, err := m.List(c, uri, &manager.ListArgs{Page:0, PageSize:1}) // also runs share validity/password
...
rx, resumed, err := eventHub.Subscribe(c, parent.ID(), requestInfo.ClientID)
3. Single-file share Root swaps the share root to the owner parent (share_navigator.go):
n.shareRoot = newFile(nil, share.Edges.File)
...
if n.shareRoot.Type() == types.FileTypeFile {
n.singleFileShare = true
n.shareRoot = n.shareRoot.Parent // <-- owner-side parent folder
}
4. To returns that parent for the bare root URI (share_navigator.go):
elements := path.Elements()
if len(elements) == 1 && n.singleFileShare { return latestSharedSingleFile(...) } // only when URI names the file
...
return current // current == shareRoot == owner parent folder
これらの製品をお使いですか？サイトをスキャンして、脆弱なバージョンが公開されていないか確認しましょう。
無料でサイトをスキャンThe bare root share URI has zero path elements (URI.Elements() returns nil for path /), so the len(elements)==1 guard is skipped and To returns the parent folder. dbfs.List returns that as parent, so parent.ID() is the owner parent folder's real ID.
5. Children masks the broader parent — for singleFileShare it returns only []*File{sharedFile}, so the recipient's listing shows just the shared file even though the subscribed topic is the whole parent.
6. Publication fans out to ancestor topics with only a client-ID filter (dbfs/events.go):
func (f *DBFS) getEligibleSubscriber(ctx, file, checkParentPerm) []foundSubscriber {
roots := file.Ancestors()
for _, root := range roots {
subscribers := f.eventHub.GetSubscribers(ctx, root.Model.ID)
subscribers = lo.Filter(subscribers, func(s eventhub.Subscriber, _ int) bool {
return !(requestInfo != nil && s.ID() == requestInfo.ClientID) // ONLY exclude the causing client
})
...
}
}
// emit*: From: subscriber.relativePath(file) // owner-side path of the changed sibling
relativePath trims the changed file's owner path by the subscribed root's owner path, yielding the sibling's name (e.g. /Secret-Plan.pdf). No check that the subscriber is authorized for the changed file or within their share scope.
Independent validation against commit 26b6b10 in a clean sandbox.
Source-verified (static): all of (1)–(6) confirmed verbatim, including the negative direction (an explicit …/shared.txt URI resolves to the file, and oss/qiniu-style flows are irrelevant here).
Dynamic (control-flow executed): the full binary is not buildable offline (modules behind an unreachable proxy, embedded frontend, DB/eventhub). The reseacher ran two harnesses:
net/url-based check of the linchpin — the bare root share URI yields 0 path elements (so To returns the parent), while …/shared.txt yields 1 (returns the file). This is the subtle point on which the whole finding turns, and it holds.Root/To/getEligibleSubscriber/relativePath driving the end-to-end flow:[1] single-file share root URI -> m.List parent = "docs" (id 10), NOT shared.txt (id 11) -> subscribed to owner parent
[2] owner renames /docs/Secret-Plan.pdf -> client 'attacker' receives: from="/Secret-Plan.pdf" file_id=12 (topic 10)
[3] CONTROL: event caused by attacker's own client id -> suppressed (the only filter)
[4] CONTROL: explicit URI 'shared.txt' -> resolves to file (id 11) -> no sibling events
shared.txt from /docs, which also contains Secret-Plan.pdf.Files.Read, with the share password if any) opens the event stream on the share root:
GET /api/v4/file/events?uri=cloudreve%3A%2F%2F<share-id>%40share
Cookie: cloudreve-session=<recipient-session>
X-Cr-Client-Id: <uuid>
Accept: text/event-stream
Secret-Plan.pdf.event: event
data: {"type":"rename","file_id":"<hashed>","from":"/Secret-Plan.pdf","to":"/Secret-Plan-v2.pdf"}
Expected: the recipient only receives events for the shared file. Actual: the recipient receives activity events for unshared siblings in the owner's parent folder.
A single-file share recipient gains a real-time feed of file-activity metadata for the owner's parent folder — sibling names, operation types, and rename targets they were never granted access to. No file contents are exposed.