GHSA-vg99-7gj7-2fr5

Summary

/api/block/getRefIDs filters its results for reader roles through a helper that checks only the visibility tiers. The password tier is not checked, because the helper does not receive the request context and therefore cannot evaluate the publish auth cookie. A reader who has not entered a document's publish password learns that the document references a given block.

A function ten lines away in the same file does perform the full check, on the same input type.

Details

Route, identical at eef105683 (kernel/api/router.go:235) and dev a7ae96ce (:245):

ginServer.Handle("POST", "/api/block/getRefIDs", model.CheckAuth, getRefIDs)

No CheckReadonly, no CheckAdminRole.

The filter chain. getRefIDs (kernel/api/block.go:631) checks isEncryptedNotebookDeniedForPublish, calls model.GetBlockRefsInBox, then for read-only roles:

publishIgnore := model.GetInvisiblePublishAccess(publishAccess)
refDefs, originalRefBlockIDs = model.FilterRefDefsByPublishIgnore(publishIgnore, refDefs)

FilterRefDefsByPublishIgnore (kernel/model/publish_access.go:1324) collects the reference and definition identifiers, resolves their block trees, and delegates the decision to FilterBlockTreesByPublishIgnore (:1314), whose entire body is:

for id, bt := range bts {
    if CheckPathAccessableByPublishIgnore(bt.BoxID, bt.Path, publishIgnore) {
        ret[id] = bt
    }
}

Inside that helper, CheckPublishAuthCookie, GetPathPasswordByPublishAccess, checkBlockTreeAccessableByPublishAccess and password all appear zero times.

The complete check exists in the same file. kernel/model/publish_access.go:431:

func checkBlockTreeAccessableByPublishAccess(c *gin.Context, publishAccess PublishAccess, bt *treenode.BlockTree) bool {
    if bt == nil || IsEncryptedBoxDeniedByPublishAccess(bt.BoxID) {
        return false
    }
    publishIgnore := filterDisablePublishAccess(publishAccess)
    passwordID, password := GetPathPasswordByPublishAccess(bt.BoxID, bt.Path, publishAccess)
    return CheckPathAccessableByPublishIgnore(bt.BoxID, bt.Path, publishIgnore) &&
           (password == "" || CheckPublishAuthCookie(c, passwordID, password))
}

Same package, same file, same *treenode.BlockTree input. One takes the context and evaluates the password; the other does not receive it and structurally cannot.

Route-level contrast. The adjacent getChildBlocks and getTailChildBlocks both carry model.CheckAdminRole.

Note on a prior assessment. getRefIDs has been described as correctly filtered because it calls a publish-access filter. It does. The filter it calls covers the visibility tiers only.

Proof of Concept

Kernel 3.7.2, publish mode on port 6808, Publish.Auth.Enable false, anonymous client. A public document referenced from a second document whose publish tier was changed between runs. getRefIDs was called anonymously each time.

| Tier of the referring document | Anonymous result | |---|---| | Public | reference returned (baseline) | | Password-protected | reference still returned | | Hidden | [], filtered | | Forbidden | [], filtered |

The hidden and forbidden rows confirm the filter runs and works. The password-protected row is the defect.

Impact

An anonymous reader in publish mode, or any publish RoleReader, learns that a password-protected document contains a reference to a given block, without entering that document's password, and receives the block identifiers involved.

Scoped precisely: the response carries identifiers only. type RefDefs { RefID string; DefIDs []string }, returned alongside originalRefBlockIDs, a map of identifier to identifier. There is no reference text, title or content. The disclosure is the existence of a relationship, plus identifiers usable as input to other endpoints.

Confidentiality only.

Suggested fix

Thread *gin.Context into FilterRefDefsByPublishIgnore and FilterBlockTreesByPublishIgnore, and use checkBlockTreeAccessableByPublishAccess in place of the bare CheckPathAccessableByPublishIgnore call, so the password tier and the encrypted-box check are both applied.