GHSA-mfrj-v65r-979c SiYuan: Publish-access filter on renderAttributeView leaves related-database content unfiltered and fails open on non-block first columns

• Go github.com/siyuan-note/siyuan/kernel: < 0.0.0-20260724121519-426991d155c0 → fixed in 0.0.0-20260724121519-426991d155c0

CVE: This vulnerability corresponds to CVE-2026-72798. Summary `renderAttributeView` correctly applies the reader publish-access filter, but the filter's row-accessibility decision is keyed solely to the row's first cell, and it never inspects the remaining cells' values. Relation and Rollup cells carry mirrored content from a *different* database, so a row belonging to a published database can hand an anonymous reader the contents of a related database whose host document is hidden, publish-forbidden, or password-protected. Separately, when the first column is not a block value the accessibility check is skipped entirely and the row is returned unchecked. Note: This is distinct from the previously reported password-tier omission in the same function that concerns the row's own primary block, whereas these two defects concern (a) other cells' related-database content, which no row-level check covers and (b) rows where the first cell is not a block at all. A fix to the row-drop condition alone would close neither. Details `renderAttributeView` applies the filter (`kernel/api/av.go:68`): ```go retDataMap["view"] = model.FilterViewByPublishAccess(c, publishAccess, retDataMap["view"].(av.Viewable)) ``` Inside `FilterViewByPublishAccess` (`kernel/model/publish_access.go`): ```go if row.Cells[0].Value.Block != nil { bt = treenode.GetBlockTree(row.Cells[0].Value.Block.ID) } if bt != nil { if !CheckPathAccessableByPublishIgnore(bt.BoxID, bt.Path, publishIgnore) { row = nil // drop } } // every other cell in the row is returned as-is ``` (a) Relation and Rollup cells leak the related database. These value types carry mirrored content, not just references: ```go type ValueRelation struct { BlockIDs []string; Contents []*Value } type ValueRollup struct { Contents []*Value } ``` The render pipeline populates them from a different attribute view e.g. `kernel/model/attribute_view.go:2731`: ```go v.GroupVal.Relation.Contents = []*av.Value{ relationDestAv.GetBlockValue(groupValue) } ``` `relationDestAv` is a separate database that may live in a hidden, publish-forbidden, or password-protected document. When a published database's row survives the filter (because its column-0 document is public), its Relation and Rollup columns return the related, non-published database's content block text, titles, and mirrored column values. `FilterViewByPublishAccess` performs no publish-access evaluation on `Relation.Contents` or `Rollup.Contents`. (b) Fail-open when column 0 is not a block. `bt` is assigned only when `row.Cells[0].Value.Block != nil`. If the first column is a non-block type (Relation, Text, …) or the row is detached, `bt` remains `nil`, the `if bt != nil` guard is skipped, and the row is returned with no accessibility check at all. Column order is user-reorderable, so any database whose first column is not the document block bypasses row filtering entirely. Verified at `origin/master` (`eef105683`). Proof of Concept Precondition: publish mode enabled (default port 6808); anonymous when `Publish.Auth.Enable` is `false`. Two databases: DB-A hosted in a published document, DB-B hosted in a publish-forbidden or password-protected document, with a Relation column in DB-A pointing at DB-B and containing a distinctive marker value. (a) Related-database content disclosure: ``` POST http://127.0.0.1:6808/api/av/renderAttributeView {"id":""} ``` Rows of DB-A are returned (correctly, since its host document is public), and their Relation/Rollup cell `Contents` include DB-B's block text and mirrored column values, despite DB-B's host document being excluded from publishing. (b) Fail-open row: Reorder DB-A so its first column is a non-block type (or use a detached row), mark its host document publish-forbidden, and request the same endpoint the row is returned without any accessibility evaluation. *Verification status:* both defects are confirmed by code inspection at `origin/master`. A live demonstration requires a build from HEAD with two linked databases; available on request. Impact An anonymous reader (publish mode with auth disabled) or any publish `RoleReader` can read content from databases whose host documents are hidden, publish-forbidden, or password-protected, by requesting a *published* database that relates to them. Because relation graphs are commonly used to link a public index to private detail records, this exposes exactly the data the publish boundary is meant to withhold. The fail-open path additionally returns rows with no accessibility check whenever the first column is not a block value, which is a user-controlled layout property. Confidentiality-only. Suggested fix In `FilterViewByPublishAccess`: 1. For each retained row, evaluate every `Relation.Contents` and `Rollup.Contents` entry against `CheckBlockIdAccessableByPublishAccess` (including the publish-password tier) and drop or mask entries that fail. 2. Fail closed: when `row.Cells[0]` has no accessible block (`Value.Block == nil` or `bt == nil`), drop the row rather than returning it unchecked.