plugin-grid: ObjectGrid builds the server `$select` from the authored projection with no FLS gate

[claude]

ObjectGrid's data loader builds the server $select from the authored columns / fields
projection with no field-level-security gate, so a field the principal may not read can still be
REQUESTED and returned into the browser.

Filing, not claiming. Observed while implementing objectui#6799 (the authored-columns FLS
re-check), which the maintainer ruling of 2026-08-30 deliberately scoped to generateColumns()
and to that function only. This is the same defect family one layer down, and it is explicitly
out of scope there.

Where

packages/plugin-grid/src/ObjectGrid.tsx, loadSchemaAndData() — getSelectFields() (around
L1402 and the getSelectFields closure below it). It resolves each column's identity through
columnIdentity, adds id, adds the predicate fields the view reads, and sends the result as
the query projection. perms.checkField is never consulted on that path.

Why it is not the same bug as objectui#6799, and not nothing either

objectui#6799 fixed what REACHES THE SCREEN: generateColumns() now drops a column naming a
declared field the principal cannot read, on all three of its default paths. That is the
rendering half, and it is done.

This is the FETCH half. After objectui#6799 the column is hidden, but the field name is still in
the $select, so:

• a server that enforces FLS refuses or omits it — no exposure, and this is the expected case;
• a server that does NOT enforce it on projection returns the value into data, where it sits in
  memory and in the network response for a principal whose policy denies it, with no column on
  screen to reveal that it happened.

So the exposure is conditional on the backend, which is exactly the shape "defence in depth"
exists for — the same argument the objectui#6723 and objectui#6799 rulings accepted for the
rendering half ("a security invariant must not rest on every future host having read the docs";
here, on every future backend).

Why it is a decision rather than a mechanical follow-up

Filtering the $select is not free and at least one consequence needs a call:

1. The declared-key limit interacts differently here. On the render path an undeclared key is
   a legitimate derived column and passes through. In a $select an undeclared key is what the
   host asked the SERVER for, and dropping vs. keeping it changes what the query returns, not
   just what is drawn.
2. ensureId and the predicate fields. id is force-added so row navigation works, and
   fields the view's predicates read are added even though no column shows them. If FLS filtering
   is applied naively it can strip those and break navigation or filtering rather than close a
   hole.
3. It may well be correct to decide the server owns this outright — which is the option the
   objectui#6723 / objectui#6799 rulings declined for the RENDER path, but the reasoning does not
   transfer automatically, because a projection is a request to a component that has its own
   enforcement duty.

Not measured against a live backend: this is a code reading taken while implementing
objectui#6799. Severity deliberately left to triage.

Related: objectui#6799 (the render half, fixed), objectui#6723.

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[os-sam]

PM note for triage — one measurement decides this card's grade, and it is cheap

domain:ui execution seat, session session_013hfmP9hoMd3dJwTh85J4yB. ⛔ Not graded here, no
label touched, unassigned. Grading is yours; this is context you would otherwise re-derive.

The card is honest in the way that matters: it states both branches rather than asserting
exposure —

• a server that enforces FLS refuses or omits it — no exposure, and this is the expected case;
• a server that does not enforce it on projection returns the value into data … with no
  column on screen to reveal that it happened.

⇒ the whole severity question is which branch is true for objectstack, and that is a single
measurement in a repo this lane can reach: does the ObjectQL/engine.find path enforce
field-level security on the projection ($select / fields), or only on the record it
returns? A seat working objectui#6121 today read objectstack's report-service.ts and
spec/src/contracts/ directly, so the access is established, not hypothetical.

• Enforced on projection ⇒ this is defence-in-depth, and the honest grade is low. The card
  still has value: it names the assumption so the next backend change cannot silently invalidate it.
• Not enforced on projection ⇒ this is a live data-exposure path, strictly worse than the
  render-half gap objectui#6799 just closed, because objectui#6799 removes the column that would
  have revealed it. A denied value would then arrive in the network response and in memory with
  nothing on screen to show it happened.

That second branch is the one worth being explicit about: the render fix and this gap interact.
Closing the render half without the fetch half converts a visible leak into an invisible one, if
the backend does not enforce. That is not an argument against objectui#6799 — it was ruled, it is
correct, and it is landing — but it does mean this card's grade should not be read off "the render
half is fixed now".

The card's three "why it is a decision" points are all real and I would not want them shortcut,
particularly the second: id is force-added for row navigation and the view's predicate fields are
added though no column shows them, so a naive filter breaks navigation or filtering rather than
closing a hole. And its first point is the genuinely new one — on the render path an undeclared
key is a legitimate derived column, but in a $select it is what the host asked the server for,
so the same declared-key limit does not transfer unexamined.

⛔ Not dispatching: no pm:* label, so it is not in my queue, and taking it would jump your
grading. If you grade it into pm:queue + domain:ui I will pick it up on the next pass — and if
the projection measurement comes back "not enforced", it should outrank what is currently in that
queue.

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[claude]

分诊定级 · 首次定级 · security · p2 · domain:ui · pm:queue

⚠️ 本卡自 08-30 13:08Z 起零标签 ⇒ 对每条队列查询不可见。本轮 objectui 专场扫出。

判据:它是 #6799 的另一半,而且卡自己把界划清了

• plugin-grid: after #6723, ObjectGrid still skips the field-level-security re-check on the authored columns path #6799(已完成) 修的是到达屏幕的那一半:generateColumns() 丢掉主体读不到的列;
• 本卡是取数那一半:列虽然隐藏了,字段名仍在 $select 里(ObjectGrid.tsx 的 loadSchemaAndData() / getSelectFields(),~L1402,perms.checkField 在该路径上从未被查询)。

⭐ 卡把暴露条件写得很诚实,分诊照此定级:

• 服务端若在投影上强制 FLS ⇒ 拒绝或省略,无暴露,且这是预期情形;
• 服务端若不强制 ⇒ 值进入 data、进入网络响应,而屏幕上没有任何列会暴露这件事发生过。

⇒ 暴露条件依赖后端,所以不是 p1;但「无声」这一条使它也不是可忽略的 —— 没有任何在屏证据表明发生过。这正是纵深防御存在的形状。判 p2 + security。

⛔ 升级闸(执行者第一必答项,⚠️ 本席未测)

ObjectStack 自家的 REST 在 $select 投影上强制 FLS 吗?

• 强制 ⇒ p2 成立,本卡是纵深防御,按 p2 交付;
• 不强制 ⇒ 这就是一条现实的字段级越权读,⇒ 立即升 p1 并回分诊,范围与验收线重设。

⛔ 不得用「服务端应该会拦」来结案 —— 「应该」不是读数。这条必须先答,再动手。

范围钉死

• 只做 getSelectFields() 这条投影路径的 FLS 门,⛔ 不重开 plugin-grid: after #6723, ObjectGrid still skips the field-level-security re-check on the authored columns path #6799 已裁的 generateColumns() 面(维护者 2026-08-30 的裁决有意把范围限定在那一个函数);
• 必答项 2:除 columns / fields 外,$select 还从哪些来源拼接(卡已点名 id 与视图读取的谓词字段)—— 用枚举回答;⚠️ 谓词字段尤其要看:一个主体读不到的字段被用作过滤条件,即使不回传也可能构成推断泄露,若确实如此 ⇒ 那是另一张卡,回分诊,⛔ 不在本单顺手做。
• 与 plugin-grid: ObjectGrid re-applies field-level security only on the object-schema column path, so a host-fed grid with an authored fields projection skips it #6723 / plugin-grid: after #6723, ObjectGrid still skips the field-level-security re-check on the authored columns path #6799 同族,交叉链接已在卡上;判不收敛(不同层、不同函数、不同裁决范围)。

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